Is it a phase? We don't know.

So let's play it out.

1. It is a phase, it is part of them exploring their social identity.

2. Is is not a phase, they are developing and exploring their sexual identity.

You won't know for sure for a while.

To be honest they probably won't work it all out for a long while (I am in my 30s and I am still working out who I am)

Once they have settled into what they are comfortable with, where do you two want to be? In a great relationship with them, having being supportive of them and helped them grow to be the best they can be? [I am assuming Yes]

Ok then, be supportive of your kid. Be their friend and shoulder told lean on (as much as you can while being a parent, you still need to set boundaries for bed time, eating veg etc)

I think that your child is getting a lot of new information, and it sounds like they are processing it as a person their age would. Good for the most part but a bit naïvely.

For example throwing out all girly things like make up (which they seems to like) because they want to be a boy, seems a bit if an over reaction.

I think it would be good to ask them to share with you what they are learning about LGBQT+ and about themself. ONLY ask questions. You don't want to come across as judging or 'trying to make them straight' (Lots of parents handle this poorly, so be kind)

Maybe start with how you come from a more traditional generation, are straight and never deeply thought about these things. Ask for their help understanding.

When you have build rapport around this (maybe more than day-week), you may want to discuss how sexual identity (and preference etc) is a spectrum. Some people identify at the girl end, others at the boy end, and others somewhere in-between. So you were wondering if is on the boy end, but still likes some girl like things like make up; but because it is 'uncool' (from social pressure that boys can't enjoy makeup) they are not 'into it anymore'. Do they think it is possible they could be into make-up as a boy? Do they think they could rock the 'cute emo boy' look if they wanted to?

If they are into that, or do not, doesn't matter. Just know that they are free to be who they are. And that can change. And that's Ok.

You don't have all the answers, but if they need a hand working out what is them. What is part of their social environment. And what they want to pick and choose to be; then you are there for them.

At the end of the day, as a parent it is our job to help our children find their way in the world and equipped to grow to be the best they can be. In this case it just happens to be giving them the tools to navigate what their social and sexual identity is.

---

Bonus:

I am not an expert please talk to a endocrinologist for more info.

Being able to treat gender dysphoria before puberty has completed, can have much better results than afterwards. Part of that treatment is taking medication to delay the onset of puberty, which allows a child to mentally mature to a point where they have a better understanding of their identity. Before making a more permanent choice. So even if it ultimately is a phase getting (temporary) treatment, with an endocrinologists guideance, early is a good idea.

It could be a phase, it may not be. Both sides of society won't like my next words and most people won't read past them. I'm not here to argue a point, but to fail to point to the complete truth is a lie of omission and I will not lie to you here. Ultimately a lot more comes into play than just "what does society think" and "what do I think" and "what does my daughter think".

First Point: Scientifically, the genders are more different genetically than you think. The X chromosome makes up about 1000 genes, the y is 1/3rd its size and has about 90 genes. The Y chromosome is like a charm bracelet where the ends are influenced by the paternal grandmother. The X Chromosome talks to its partner, and the influence of the X chromosome can be studied in Fragile X, Turner Syndrome, and Males. Basically in a male, the X asks its partner what they should do and the Y says "your beautiful you've got this" and occasionally has input. My point is the high genetic difference in how we are made. No amount of wishing or drugs changes genetics, so genetically, there is no choice to be made, only a choice of how to act. Start Sidetrack: Epigenetics doesn't replace entire chromosomes, it can suppress or encourage traits already present. Different cells in the body react differently to epigentics, so widespread epigenetics in its infancy is like getting hit with chemicals or radiation which 'can' lead to genetic disorders, cancers, metabolic disorders and degenerative disorders. It has nothing to do at this time with being able to trade an entire chromosome. Perhaps the future will see this differently. End sidetrack. Our society has embraced the idea of men and women being the exact same. To be clear: I hold them as equal, just not the exact same.

Second point: LGBT is a very hard life to live, it comes with special risks, stigmas, health issues, and all kinds of other problems, most of which can be managed with good choices. Some people want to live that life; some people feel trapped into living it. My argument is this: A heterosexual person chooses whether they marry/date/etc. or not. Just because your current orientation is different doesn't deprive you of a similar choice; just because you enjoy things the other gender enjoys doesn't make you automatically another gender. Every person has to make a decision for themselves based upon their own beliefs, religion, etc., it might be influenced, but ultimately the decision is an individual one.

As a family member, friend, or parent, the best thing we can do is love whoever it is that is making these decisions both before AND AFTER the decision, even if we don't like it. We can share our thoughts, we can share our opinions; we can share facts. If they are young enough our government holds them to a no sexual contact standard before a certain age that we should also adhere to as parents regardless of their current perceived gender identity. If we are concerned about a safety factor, we should take measures to protect them until they are at a responsible age. There is a point in time where everyone makes this "decision" for themselves, and many people don't make that "decision" right away.

My advice: do some research, let your daughter know your opinion, tell it to her in love, let her communicate how she is feeling and encourage her to do some soul searching without trying to judge her or convince her, just listen, find out if something has happened to her to make her feel this way, tell her you will love her afterwards no matter what she decides to do, then do exactly that, love her. You don't have to be nosy or bug her about it daily, it will ultimately be her "decision". I cannot conceive that pressuring her into any decision would resolve well, but you do have a right to talk to your daughter to determine what you should do. Remember, decisions aren't made in a second, they are a culmination of our past decisions. This is not a time for punishment or reward, this is a time for being a great companion and lifelong friend.

Three final things: 1. How you react when/if your child comes out will forever be in their memory. IMO, There are some scenarios which every parent should have prepared on how to react; this is one of them. 2. There are multiple resources out there, some really good Christian resources can be found at Family Life Today and Focus on the Family. 3. A recent book by Becket Cook might be helpful: A Change of Affection.

I was asked for citations: https://www.genome.gov/about-genomics/fact-sheets/Y-Chromosome-facts

https://www.genome.gov/about-genomics/fact-sheets/X-Chromosome-facts

https://www.sciencedirect.com/topics/neuroscience/x-chromosome#:~:text=The%20X%20chromosome%20is%20a,genes%20unrelated%20to%20sex%20determination.

https://en.wikipedia.org/wiki/Lie

https://ghr.nlm.nih.gov/primer/howgeneswork/epigenome

https://cmda.org/article/negative-health-consequences-of-same-sex-sexual-behavior/

https://www.nytimes.com/2020/06/15/us/gay-transgender-workers-supreme-court.html

http://www.ulifeline.org/articles/428-emotional-challenges-faced-by-lgbt-students

https://www.psychologytoday.com/us/blog/he-saidshe-said/201212/acceptance-the-foundation-lasting-relationships

https://peacefulmindpeacefullife.org/the-importance-of-accepting-people-where-they-are/

https://en.wikipedia.org/wiki/Unconditional_love

I'm appalled at the disconnect here from what the actual research says in regards to this issue.

In a systematic literature review on the elevated risk of health issues among transgender and gender variant youth (Protective Factors Among Transgender and Gender Variant Youth: A Systematic Review by Socioecological Level), there were found some consistent protective factors. First of all, let me make clear that questioning one's gender, even if it doesn't result in a permanent identification as transgender, is a form of gender variance. This means that the findings discussed in this literature review represent a form of consensus of research on how to handle youth like your teenager.

This review covered articles spanning 1999 to 2014. The data analyzed pertains to youth aged 10 to 24 years. The paper notes first:

Transgender and gender variant (GV) youth experience elevated risk for poor health and academic outcomes due mainly to social experiences of stigma and discrimination.

^{emphasis added}

Now, here are the protective factors uncovered by this study that mitigate the risks:

Within these articles, 27 unique protective factors across four levels of the ecological model were identified as related to positive health and well-being. Self-esteem at the individual level, healthy relationships with parents and peers at the relationship-level, and gay-straight alliances at the community level emerged as protective factors across multiple studies.

^{emphasis added}

The availability of transgender health and social services in schools and neighborhoods was cited as important for finding emotional support for and tangible assistance with legal and medical transitions

Now, I will note that medical transition is not something to undertake lightly. The NHS states:

Most treatments offered at this stage [children under 18 referred to specialists for gender dysphoria] are psychological, rather than medical or surgical. This is because the majority of children with suspected gender dysphoria don't have the condition once they reach puberty. Psychological support offers young people and their families a chance to discuss their thoughts and receive support to help them cope with the emotional distress of the condition, without rushing into more drastic treatments.

If your child has gender dysphoria and they've reached puberty, they could be treated with gonadotrophin-releasing hormone (GnRH) analogues. These are synthetic (man-made) hormones that suppress the hormones naturally produced by the body.

The effects of treatment with GnRH analogues are considered to be fully reversible, so treatment can usually be stopped at any time after a discussion between you, your child and your MDT.

That said, there is a lot of misinformation out there. Here are the findings of a Cornell University review:

1. The scholarly literature makes clear that gender transition is effective in treating gender dysphoria and can significantly improve the well-being of transgender individuals.

2. Among the positive outcomes of gender transition and related medical treatments for transgender individuals are improved quality of life, greater relationship satisfaction, higher self-esteem and confidence, and reductions in anxiety, depression, suicidality, and substance use.

3. The positive impact of gender transition on transgender well-being has grown considerably in recent years, as both surgical techniques and social support have improved.

4. Regrets following gender transition are extremely rare and have become even rarer as both surgical techniques and social support have improved. Pooling data from numerous studies demonstrates a regret rate ranging from .3 percent to 3.8 percent. Regrets are most likely to result from a lack of social support after transition or poor surgical outcomes using older techniques.

5. Factors that are predictive of success in the treatment of gender dysphoria include adequate preparation and mental health support prior to treatment, proper follow-up care from knowledgeable providers, consistent family and social support, and high-quality surgical outcomes (when surgery is involved).

6. Transgender individuals, particularly those who cannot access treatment for gender dysphoria or who encounter unsupportive social environments, are more likely than the general population to experience health challenges such as depression, anxiety, suicidality and minority stress. While gender transition can mitigate these challenges, the health and well-being of transgender people can be harmed by stigmatizing and discriminatory treatment.

7. An inherent limitation in the field of transgender health research is that it is difficult to conduct prospective studies or randomized control trials of treatments for gender dysphoria because of the individualized nature of treatment, the varying and unequal circumstances of population members, the small size of the known transgender population, and the ethical issues involved in withholding an effective treatment from those who need it.

8. Transgender outcomes research is still evolving and has been limited by the historical stigma against conducting research in this field. More research is needed to adequately characterize and address the needs of the transgender population.

In summary, your goal right now should be to create a supportive environment for your teenager, help build their self-esteem, and allow them to continue to engage with the LGBT community while continuing to seek therapy with professionals who understand transgender and gender variance issues. Anything less is a risk to your teenager's health.

What has been overlooked is the reasons why your daughter "suddenly" changed. She did not suddenly change and this is not a phase. Your answer(s) can be found in the first paragraph of your story. Your daughter is heartbroken and was feeling (and still feels like) a damaged ship without its sail, captain or navigation system (that's you). Since, you did not mention anything about discussing the move, helping your daughter to make new friends, engaging her and joining her in community, neighbourhood or school activities to help with the transition of a new city, new environment...new everything; then no wonder she feels lost, alone and desperate for some sort of inclusion/sense of familiarity she can include herself.

Now, it's not too late to have a heart-to-heart talk with her. First apologizing that you did not realize how difficult or how much the move affected her, her life and sense of security. Prior to speaking with her find some activities you and her can participate in that you know without a doubt she will enjoy especially anything she has not done since the move. If she enjoys the arts discuss that with her and the girl she had made friends with in art class.

Basically, what you need to do here is step up and become your daughter's confidant-no judging, a whole lot of loving, understanding and sharing. Speaking of sharing, if you have anything remotely similar that happened to you in your childhood share that with her and how you overcame. Just a thought, have you ever thought of making a visit back to your other city? If not and you can afford it surprise her with the news, make the trip and encourage her to keep in touch with your friends back home. Maybe even a simple phone call to her best friend would help ease the pain.

I hope this gives you pause for thought and reconciles your daughter in being confident in knowing who she really is.

I'm not surprised that being exposed to LGBT+ culture for the first time would be the starting point of this "phase". I know plenty of people (myself included) who settled for trying their best to perform their assigned gender before discovering they didn't have to. The pattern you're describing is not necessarily one of imitation or fitting in, but of exploring a new and previously-unknown possibility.

You can't necessarily have your "old daughter" back. This can't be forced without causing serious harm. You haven't lost your child though, you just may have been mistaken about their gender. The best thing you can do right now is to hold their gender lightly. This doesn't mean don't take it seriously, rather, give them space to explore. If one week they're a "he" and another they're a "she", go with it, use the pronouns they want, try out the name they want. Let them explore and try things on for size. You want to lower the cost of experimenting as much as possible, otherwise there will be pressure to "resolve" this as quick as possible, potentially leading to regret down the road.

It's also possible you missed your opportunity to be involved in the experimentation. If they've already made up their mind this is something you need to respect, although this amounts to the same thing: respect their choice in clothing, name, and pronouns, work with a trans-friendly doctor to delay puberty if that's what they want, and make sure they know you love them unconditionally.

And if it does turn out to be a phase? No daughter is going to grow up to resent you for allowing her to delay puberty until she was sure she wanted it. No daughter is going to resent you for taking her experiments with different names and pronouns with you, until she could truly decide for herself what she wanted to be. Even if it turns out to have just been a phase, you've given your child the empowering gift of letting them truly claim their gender as their own.

Is this a phase?

Almost assuredly. I would be shocked if many things about her don't go into flux based on her age. The eighth graders made an impression. It's ok. Solid move on getting therapy.

Is this common?

I found a quoted incidence of gender dysphoric disorder in adolescents of about 1% [Zucker KJ.Sex Health: 2017 Oct;14(5):404-411.]

However, subclinical "symptoms" are probably 10 times as common, but this is a new area of interest in medicine.

Fortunately, wearing boys clothes isn't going to hurt anyone. Maiming one's body is another thing entirely.

Definitely agree with Adam and just wanted to add that I know you love your child, and make sure they know you love them whether they choose to be called a boy or girl. Try your best to respect their decision because right now they probably need one person they can trust to just be themselves around.

You mentioned that sometimes you get some new makeup and your child gets interested but then remembers that "boys aren't suppose to like makeup." So it seems like they want to get you to accept them as a boy, but they still actually like make up, but they tried to hide that even from you.

As a part of the dysphoria, they might see girly things as "lesser" than boyish things, but I think it might be important to remind them that men can wear make up too, and not all of them are stereotypically gay (which also, nothing wrong with gay people) Your child can still like make up even though they want to be a boy, but if they change their mind in the future to being a girl that likes make up again, that's ok too. (I think it's important to not shame them for changing their mind, they're 13, and still learning)

I think it's important to let them at least explore themselves a little bit and make a decision. It seems they're willing to wait until they are 18 to make any decisions about altering their body (hopefully they will get a job and pay for the treatment themselves if they truly want it), so they have time to learn and experience until then.

Just be there and love them the best you can and let them know you love them. If you reject them and their identity right now, they might even close off to you because you just "don't understand." Not only that, it might hurt them in a way like "not even my parents love me for who I am."

You seem to have trouble believing that things fit because it's sudden and because your child was very feminine before announcing the dysphoria. This is understandable, but it's important to emphasize that this doesn't make the gender dysphoria invalid.

The are generally two forms of gender dysphoria that have been documented, early-onset gender dysphoria and late-onset gender dysphoria. The early-onset form makes more intuitive sense to many people, since it is associated with a lot of gender nonconformity and looks a lot more like a "boy trapped in a girl body" than late-onset gender dysphoria. In fact, it may make more sense to think about late-onset gender dypshoria as "girl trapped in a girl body".

Here's what the DSM says about late- and early-onset gender dysphoria:

In both adolescent and adult natal females, the most common course is the early-onset form of gender dysphoria. The late-onset form is much less common in natal females compared with natal males. As in natal males with gender dysphoria, there may have been a period in which the gender dysphoria desisted and these individuals self-identified as lesbian; however, with recurrence of gender dysphoria, clinical consultation is sought, often with the desire for hormone treatment and reassignment surgery. Parents of natal adolescent females with the late-onset form also report surprise, as no signs of childhood gender dysphoria were evident. Expressions of anatomic dysphoria are much more common and salient in adolescents and adults than in children.

Adolescent and adult natal females with early-onset gender dysphoria are almost always gynephilic. Adolescents and adults with the late-onset form of gender dysphoria are usually androphilic and after gender transition self-identify as gay men.

Not much is known about female-to-male late-onset gender dysphoria, but it is reasonable to infer that it is similar to male-to-female late-onset gender dysphoria. This form of gender dysphoria is better studied, and in particular it is known that those with late-onset gender dysphoria still benefit from transition, even though it may not logically seem like they "should". Late-onset gender dysphoria is thought to be a progressive condition, in the sense that it gets worse over time. This is in contrast with early-onset gender dysphoria, which generally remains stable beyond a certain age. You may have heard statistics finding that most trans kids grow out of it naturally. These statistics apply to early-onset gender dysphorics, but not late-onset gender dysphorics.

Another responder linked to Lisa Marchiano. My impression is that she is a quack, since she tends to ignore the context of late- vs early-onset gender dysphoria. In addition, the groups she works with tend to actively obstruct my attempts to document the outcomes of the kids they work with. She also says nonsense like "Cosmetic outcomes for natal females who transition when they are older are not significantly impacted by waiting.", which is absolutely not true.

Is she joined an LGBT club and participated in a lesbian play, it's hardly surprising that this would bring thoughts of transgenderism to her mind.

Which came first? Did she join the LGBT club because she was thinking she might want to be transgender? Or did she join out of curiosity, or because a friend was a member, and from there went to the transgender thoughts? Your first paragraph makes it sound like she just joined because her friend did, but whether that's the reason or a coincidence is hard to say.

You say that she cycled through several "sexual identities". This could mean that she's just playing games, experimenting, seeing what reaction she gets.

Have you asked her why she wants to be a boy?

You say that she was separated from a boy she really liked. Not quite the same, but I've met a couple of women who became lesbians after having very bad break-ups with boyfriends or husbands. It's an easy amateur psychoanalysis that the thinking, conscious or unconscious, was, "This man treated me badly. Men are all jerks. I'd be better off if I formed relationships with other women." There might be something similar here. "Being separated from my boyfriend was painful. I don't want to ever go through that again. I'd be better off if I was a boy so I didn't get attached to another boy like that again."

Was she particularly feminine before? You might ask her if she misses feminine pleasures. Like, "wow, why would you want to be a boy and miss out on all the fun of being a girl?"

The question of whether or not this is a phase isn't something that can be answered by us. That answer will need to be answered through a combination of your child's development, work with professional therapists, and time.

Ultimately, though, the bigger question is how you, as a parent, approach the situation. If this isn't a phase, it is risky to treat it like a game, or something to fight against or ignore -- Adam has outlined gender dysphoria pretty thoroughly, and I agree that it needs serious consideration.

But either way:

It is OK to feel disappointed and confused about this. A changing teenager is an exhausting parenting challenge in any situation, and you potentially face bigger changes than most people. You feel like you're losing a person you thought you knew, you miss your "girly" daughter, you don't want to see your child unhappy, you hate the smell of Axe body spray. (Side note: I'm with you on that one, it's pretty yucky.) It's normal to need time to process, to learn, and even to some extent to grieve.

However, you can't force your child to be happy with the same things that make you happy. Dealing with something like changes tastes in music is a pretty common teenage situation -- you're currently encountering a larger, more complicated, and more sensitive situation. Whether this is gender dysphoria or a phase, your child is exploring gender identity and gender presentation and finding what makes them personally comfortable. As a parent, you need to provide a safe space to support that exploration. Arguing that they don't know what they're feeling, that their choices are wrong, whatever... anything like that just leads to resentment, depression, and an erosion of trust. And trust is important, because you want your kid to be able to come to you with their problems so you can help.

And, this is still your child. You still love them, you still want them to be happy, you still want them to be safe. Changes, even big ones, do not affect those fundamental bonds.

Find a family therapist in addition to her personal therapist. This provides a safe space where you and your child can discuss these issues together, with a professional to guide conversation so topics are focused and constructive. Absolutely keep the individual therapy for your child, because that's their personal safe space -- but this would give you a way to work and understand the situation together. There, you can be honest with your child that you're confused -- that could be a very positive communication to have, explaining that you want to understand and accept but it's a big change and will take time. I guarantee that even those tearful accepting "coming out" videos are only one small piece of the journey. It is OK to "shop around" for therapists (for you, for her, or for you both) as you start and continue this journey. Sometimes a therapist just isn't a good personal fit; if you don't feel like you can trust them with your feelings, it won't be as helpful.

Personally speaking, I have a close friend whose child is trans, and it's taken me a fair amount of time to adapt: I still use the wrong pronouns and the wrong name. There are years of habit that I am trying to break, and I sometimes mess up. I still tear up a little when I see adorable pictures of a very different person from years ago. And that's not even my kid. But no matter what emotion I have about it, this is a much harder process for that child, and so I do my best to be there for them.

It is not bad to want something, or want to be something, even when you are 13 years old. I remember wanting a lot of things back then, and indeed I didn't immediately get what I wanted.

Another consideration. If she would be joining a LARP club, she would suddentlty want to be an elf (maybe a goblin also, but likely an elf). But as she were joining LGBT club instead, she now wants to be a boy. Not that it requires any more action in the latter case than in a former.

I imagine it is not even a phase but a game. But, why not wait and see if it sorts out in the following years?

Preface
The topic of teens wanting to change genders is a very delicate one and also one without much information available. There are plenty of people who want to argue their ideological viewpoint, but that isn't helpful when you're dealing with a real situation with someone you love.

The key term being discussed is Gender Dysphoria.

Gender Dysphoria involves a conflict between a person's physical or assigned gender and the gender with which he/she/they identify

An Article in Quillette, which I think your daughter should read, states:

In the past decade, however, a new presentation of gender dysphoria has suddenly become widespread, in which teens or tweens come to identify as transgender “out of the blue,” without any childhood history of feeling uncomfortable with their sex. Experts have dubbed this presentation rapid onset gender dysphoria, and are beginning to study it.

The American Psychiatric Association states

For many children the feelings do not continue into adolescence and adulthood.

WebMD states

People with gender dysphoria have higher rates of mental health conditions

The previous 3 statements are not made for any other reason than to point out the seriousness, complexity, and the gentleness that this issue should be taken with. They also both serve as further resources a reader may use to do their own research.

With this minimal amount of information about the topic I'd like to offer some reasonable information on how to handle it. I'm going to the anecdotal research by a Social Worker with experience in these issues. The source information is not a long read and I suggest you simply go read it yourself. There are 2 posts that discuss having a teen with Gender Dysphoria (the author is the same author who wrote the article in Quillette above):
Part 1
Part 2

Summary
Don't fall into the trap arguing about gender dysphoria. Keep in mind how much you love your child as you go through this. Try to ask questions and understand why your child feels this way.

The ideology of innate gender identity doesn’t make much sense of a lot of the time, and many young people seem to sense this

At all costs avoid shaming or punishing your child over gender identity. At the same time, you can choose to not agree to the identity. Choosing your response needs to be a unique choice based on personal information no one here will have. Part 1 discusses this in more detail.

Challenging a child’s beliefs should always be done without anger. As much as possible, it ought to be done respectfully and with genuine empathy for the child’s suffering. Some parents have had good success with carefully timed, short reality-based statements, delivered with authority but not anger

Remember children are children because they simply are not ready to live on their own. They don't know enough and they are not mature enough. It is your responsibility to be in charge and keep your child safe during this time.

It is really hard to research this stuff on your own when your world feels like it is falling apart. I genuinely believe the content posted by Lisa Marchiano in the 3 main links is reasonable. It is also all I have been able to find. This is a very new phenomenon.

Note on Social Media
There is strong evidence about the negative influence of social media on teens and tweens. That is not the main topic at hand, but from your question it seems to be a major impact on this specific situation. There are other questions which have answers to this topic.

More Personal to you
I could give you many more opinions, but there are many questions. I wonder how much you know about the therapist you've chosen, how much you know about what your daughter does on social media, and of course what core issues were that led to the therapist in the first place. There is a lot for you to unpack, my questions are rhetorical for you to answer.

Appendix 1: American Academy of Pediatrics
Further reading is a PDF printed by the Children's Hospital of Chicago by the American Academy of Pediatrics. They officially support Affirming gender change in children, however there is a group of pediatricians who actively reject that position.

At the least, if your daughter does start to consider therapy in the future with or without your consent, please review pages 39-41 and see the side effects of testosterone therapy.

Irreversible Effect of Testosterone Therapy:
Lower voice Increased Hair Growth
Mustache and Beard Growth
Male Pattern hair loss and baldness
Genital Changes
Loss of Fertility

Side Effects of Testosterone Therapy;
Cardiovascular Risk
Increased Weight gain
Increased Triglyscerides
Increased Blood Pressure
Insulin Resistance
Hepatotoxicity (liver disease)
Aggression
Irritability
Headaches
Acne
Polycythemia (increase change of heart attacks, blood clots, and more)
Increased risk for breast cancer
Increased risk of Endometrial cancer

Post Research Note
It appears there is a good amount of support for Gender Dysphoria in some national groups like the APA. However, no reading of the definition of Gender Dysphoria has shown to be anything other than supporting what people feel. I cannot find genuine objective information on the topic.

Post Research Note 2
Parenting Stack Exchange is not the place for questioning the topic of Gender Dysphoria in general. I opened a self-admittedly long winded question on the Psychology & Neuroscience Stack Exchange site where I address some of my concerns over the general validity of the APA holding a stance that supports and affirms gender reassignment, especially in children.

Post Research Note 3
I think there is a huge gap between the reality of this topic and how we talk about and understand it. I have posted a position on this gap at the Psychology & Neuroscience Stack Exchange site here.