Introduction
Hormone therapy for transgender men aims to masculinize the body. This includes building muscle, losing fat, and shifting fat from a feminine pattern (hips/thighs) to a masculine one (stomach). Testosterone usually does a good job here. Over the first year or two, trans men typically gain about 10% more muscle and lose roughly 10% of their body fat [1]. Fat moves away from the hips and thighs and toward the waist. This creates a more masculine shape. Long-term studies confirm that trans men on T end up with more muscle and less subcutaneous fat than cis women, getting very close to a cis male profile [2].
However, not everyone gets the results they want. Age, genetics, and lifestyle play huge roles. Trans men who transition later in life, or those who can't train heavy weights, might find their muscle gains stall. Others might still have stubborn fat pockets in "female" areas or develop too much belly fat, which isn't healthy or aesthetically pleasing. Because of this, some people are looking into extra therapies to help. One option is using the growth hormone (GH)/IGF-1 axis to boost muscle building and fat burning alongside testosterone.
GHRH analogs like tesamorelin are peptides that tell the pituitary gland to release growth hormone. This raises levels of IGF-1. In people with HIV who have belly fat issues, tesamorelin has been proven to reduce that deep visceral fat and add some lean mass [4]. Since cisgender male puberty involves a huge spike in both Testosterone and GH, adding a GH stimulant for adult trans men might copy that synergy. This paper looks at why we might use GHRH/GH in FTM therapy, the potential benefits, and the risks.
Sex differences in muscle and fat, and GAHT effects
Men and women carry weight differently. Men generally have more muscle and less body fat. They also store fat internally around the organs rather than on the hips and thighs. Hormones drive these differences. Testosterone builds muscle and puts fat on the belly, while estrogen puts fat on the lower body.
When trans men start T, their bodies shift toward that male pattern. In the first 6 to 12 months, strength and muscle size go up significantly [1]. The waist gets a bit bigger as visceral fat grows, and the hips get smaller. Over the long term, these changes get better. Trans men on T for years have much more lean mass and less fat under the skin compared to women [2].
But not every trans man will get the same muscularity as a cis man who went through a male puberty at 14. GH and IGF-1 levels drop as we age. A trans guy starting at 30 or 40 won't have that natural growth hormone boost that a teenager has. This means muscle gains might be slower or more limited. Also, some men end up with the "worst of both worlds" by gaining belly fat from testosterone but keeping stubborn fat on the thighs. This is where GHRH analogs come in. They could help sculpt the body by burning fat and helping muscle growth in ways testosterone can't do alone.
GHRH and GH: mechanism of action and metabolic effects
Growth hormone-releasing hormone (GHRH) is a signal the brain sends to release growth hormone. Synthetic analogs like tesamorelin mimic this signal. GH is powerful stuff. It burns fat aggressively and builds muscle and bone. During puberty, high GH and Testosterone work together to create rapid growth. Testosterone actually boosts GH output, which is part of why men usually have different body compositions than women [3].
GH is especially good at targeting visceral fat, the deep fat around your organs. At the same time, it helps muscles hold more water and protein. For people with HIV, tesamorelin reduced visceral fat by about 11% in 6 months and up to 18% in a year [4]. It didn't strip away the healthy fat on the limbs too much, but it did shift the overall look to be leaner and more muscular. This is basically the opposite of what aging does to the body.
For a trans man, activating this axis could amplify the effects of testosterone. Higher IGF-1 levels help muscle fibers grow larger. It might also help burn off those lingering feminine fat pads on the hips or lower abs. Metabolism experts sometimes say GH moves fat "from an apple to a pear" shape, meaning it gets rid of the unhealthy "apple" belly fat [9]. By getting rid of that deep fat, you reveal the muscle underneath.
It's important to know that GHRH isn't a magic masculinization button. It won't grow a beard or lower your voice. Only testosterone does that. But it can optimize the body's environment for muscle growth. It's like supercharging the "second puberty" that HRT starts. Studies in older men show that combining T and GH works better than T alone for building lean mass [3].
Evidence and experience with GHRH/GH in FTM individuals
We don't have direct clinical trials on this for trans men yet. Most of what we know comes from HIV studies or bodybuilders. In HIV patients, we know it works to fix body shape. Bodybuilders use it to stay lean while adding muscle.
In the trans community, evidence is mostly anecdotal. Some users on forums have reported using peptides like sermorelin or ipamorelin. One guy mentioned using sermorelin for 3 months and seeing better fat loss and muscle retention [7]. Another planned to stack tesamorelin to get better results. While these are just stories, they show that people are trying it and seeing some benefit.
Dr. Will Powers has mentioned that while high GH levels in teens help transition results, using high doses in adults is risky. He warns about acromegaly, where your bones get too big and you look coarse rather than masculine [5]. Standard guidelines like WPATH don't recommend GH for adults because of these risks and the high cost [6].
There is some use of GH in trans youth to help with height, but that is a very specific medical case involving puberty blockers and open growth plates. It doesn't really apply to adults trying to get buff.
Potential endocrine interactions
Adding GHRH to a trans man's regimen is usually safe hormonally. Testosterone and GH work well together. GH won't mess with your T levels or bring your Estrogen back. If anything, they have a synergistic effect. Higher IGF-1 might make your body use the testosterone more efficiently for muscle growth.
One nice side effect is that reducing belly fat can improve insulin sensitivity and cholesterol, which sometimes get worse on Testosterone. However, you have to be careful because GH itself can raise blood sugar if the dose is too high.
Will it make "bottom growth" bigger? Probably not. Genital growth is driven by androgens. While GH helps penis growth in kids, in adults it doesn't seem to restart that growth. It also won't affect ovaries or make you ovulate if you are on T.
Safety considerations and side effects
You need to be careful with growth factors. Here is what to watch out for:
- Water Retention: GH makes you hold water. You might get puffy ankles or tight rings. It can raise blood pressure. If you swell up more than a few pounds, the dose is too high.
- Joint Pain: Carpal tunnel and aching joints are classic signs of too much GH. About 15% of people in trials had some joint pain [4]. If your wrists go numb, stop taking it.
- Diabetes Risk: GH fights insulin. It raises blood sugar. If you are pre-diabetic, GH could push you into full diabetes. You must check your fasting glucose. Eating low carb helps.
- Acromegaly: This is the scary one. If you take too much for too long, your jaw, nose, and hands can grow permanently. It doesn't look good; it looks like a disease. Keep doses reasonable to avoid this.
- Cancer: IGF-1 promotes cell growth. If you have a history of cancer, you should probably avoid GH. There isn't hard proof that it *causes* cancer in healthy people, but it's a risk factor to consider.
Discussion: Efficacy and role in masculinization
Expect gradual changes, not miracles. In studies, it took 6 to 12 months to see that 15% drop in belly fat. For a trans man, this might mean the waist gets a few centimeters smaller and muscles look fuller and harder. If you don't diet, the scale weight might not change much because you are swapping fat for muscle.
This therapy works best for guys with a "beer belly" or visceral obesity, older guys whose natural GH is low, or bodybuilders trying to break a plateau. It helps cut stubborn fat pads.
Does it interfere with masculinization? No. It won't stop your beard or voice changes. It won't shrink your bottom growth. It basically just helps the gym work show up better.
Conclusion
GHRH analogs like tesamorelin are an interesting tool for trans men who want to push their body composition further. By boosting GH and IGF-1, they create an environment that burns fat and builds muscle, similar to a teenage male puberty. Evidence from other groups supports the idea that this can work.
However, it's experimental. It's not standard care. It comes with risks like joint pain and blood sugar issues. It should never replace Testosterone. It is strictly an add-on. If you decide to try it, start low, go slow, and monitor your blood work closely.
Typical Dosages and Monitoring Summary:
- Tesamorelin: 2 mg injected daily (subcutaneous). Some start at 1 mg to test tolerance.
- Ibutamoren (MK-677): 10–25 mg pill daily. This is an oral option but often causes more hunger and water weight.
- CJC-1295 / Ipamorelin: A common peptide stack. Dosages vary, but often 100mcg/300mcg.
Monitoring: Check IGF-1 and Fasting Glucose after 1 month. If IGF-1 is too high, lower the dose. If sugar goes up, stop. Aim to see real changes in the mirror by month 6. If not, it's not worth the money or risk.
References
[1] Van Caenegem E, Wierckx K, Taes Y, et al. Body composition, bone turnover, and bone mass in trans men during testosterone treatment: 1-year follow-up data. European Journal of Endocrinology. 2015;172(2):163–171.
[2] Van Caenegem E, Wierckx K, Taes Y, et al. Bone mass, bone geometry, and body composition in female-to-male transsexual persons after long-term cross-sex hormonal therapy. The Journal of Clinical Endocrinology & Metabolism. 2012;97(7):2503–2511.
[3] Sattler FR, Castaneda-Sceppa C, Binder EF, et al. Testosterone and growth hormone improve body composition and muscle performance in older men. The Journal of Clinical Endocrinology & Metabolism. 2009;94(6):1991–2001.
[4] Falutz J, Allas S, Blot K, et al. Effects of tesamorelin (TH9507), a growth hormone–releasing factor analog, in HIV-infected patients with excess abdominal fat: a pooled analysis of two Phase 3 trials. The Journal of Clinical Endocrinology & Metabolism. 2010;95(9):4291–4304.
[5] Powers W. Personal communication and community discussions regarding GH risks in adult transition. Reddit /r/DrWillPowers. 2024.
[6] Coleman E, Bockting W, Botzer M, et al. Standards of Care for the Health of Transsexual, Transgender, and Gender-Nonconforming People, Version 7. International Journal of Transgenderism. 2012;13:165–232.
[7] Anecdotal reports from community discussions (e.g. "AI and Peptides"). Reddit /r/ftm. 2013.
[8] Sivakumar G, Poon E, Catt S, et al. Growth hormone axis drugs for HIV lipodystrophy: a systematic review. HIV Medicine. 2011;12(8):453–462.
[9] Alser M, Elrayess MA. From an Apple to a Pear: Moving Fat around for Reversing Insulin Resistance. International Journal of Environmental Research and Public Health. 2022;19(21):14251.
Medical Disclaimer: This document contains medical information that should be reviewed by qualified healthcare professionals. Dosages and protocols may vary based on individual circumstances, medical history, and healthcare provider recommendations. This information is for educational purposes only and does not constitute medical advice.