The Trans Directory

FTM Myths and FAQ

7 min read

Testosterone comes with a lot of folklore that comes from gym culture, from well-meaning forums, and from outdated medicine. If something you heard has you worried, you’re in good company, and you’ve come to the right place. Here’s the reality on the biggest myths. (UCSF’s patient FAQ on testosterone is a good companion read.)

Myth vs reality

MythReality
”T turns you aggressive. ‘roid rage.‘”Not at therapeutic (medical) doses. “Roid rage” comes from anabolic-steroid abuse at 10-100× medical doses. even at 600 mg/week (6-12× a typical transmasc dose), 84% of men in the classic RCT had minimal psychiatric effects.1 Studies of trans men on T find no aggression increase at 12+ months; some show decreases; serum (blood) T level doesn’t track anger.23 Early, temporary irritability is possible due to the effective second puberty which is usually fixable by smoothing level swings.
”T will make me taller / change my bones.”No height gain once growth plates (the growing ends of your bones) fuse during mid-to-late teens for AFAB puberty. T doesn’t restructure adult facial bone either. it maintains/increases bone density, which protects you long-term.45
”More T = faster/bigger changes.”UCSF, verbatim: “Once within the normal male physiologic range, there is no evidence that higher doses/levels of testosterone result in a greater degree of virilization.”6 Extra T adds side effects (erythrocytosis/ too many red blood cells, acne, hair loss) and excess T aromatizes (converts) to estradiol, a form of estrogen. Genetics set the ceiling on changes.
”Injections are stronger than gel.”All formulations reach the same male-range levels when the dose is adjusted. The real difference is steadiness (how smooth your levels stay between doses), cost, routine, transfer risk but not potency.67
”T is birth control.”Dangerously false. 33% of people on T whose periods had stopped showed recent ovulation (an egg being released) in one 2024 study; pregnancies on T are documented. You need real contraception. see FTM Periods and Fertility.8
”T destroys your liver.”Modern bioidentical T is not hepatotoxic (toxic to the liver). The reputation belongs to oral methyltestosterone, a bodybuilding-era drug no longer prescribed.69
”T makes you permanently infertile.”Not proven either way. ~80% resumed menses (periods) within 6 months of stopping in the key study, and pregnancies after years of T are documented but permanent loss is possible and unpredictable. Plan both ways.10
”You must stop T before surgery.”An outdated blanket rule. The stop ~1-4 weeks convention existed “despite the absence of evidence”; studies show no clot increase when T continues, and SOC8 supports continuing. Coordinate with your surgical team.11
”You need T (or surgery) to be really trans.”No??? SOC8 treats social transition, hormones, and surgery as independent options “whether the person is a transgender man, transgender woman, or a nonbinary person” and you should too. Identity isn’t decided by a medical history.11

Frequently asked questions

Will T change my face? Through fat redistribution, muscle, skin texture, and facial hair, not bone. Changes are measurable on 3D scans by 3-12 months; in one facial-morphology study, 95.5% of trans men (mean ~8.6 years on T) were read as male. Expect the “final” face at 2+ years; genetics and age at start shape the outcome.1213

Can voice training do what T does? They do different jobs. T physically thickens the vocal cords and training can’t replicate that anatomy change, and T’s voice drop is permanent. But up to ~20% of trans men still find their pitch too high after a year, and for them a speech-language pathologist (a voice therapist for resonance, control, intonation) is the recommended next step.14 Some people train instead of T, or alongside low-dose T. See Voice Training. The Cleveland Clinic’s voice masculinization page gives a sense of the clinical options.

Is bottom growth normal? What should I expect? Completely normal and near-universal. typically ~1-4 cm, often the first noticeable change (starting ~1-6 months, maximal by ~1-2 years), and permanent. Early hypersensitivity (extra sensitivity) or discomfort is common and usually settles within ~6 months. Size varies widely by genetics. Taking finasteride (for hair loss) can blunt bottom growth, see FTM Risks and Side Effects.1516 FOLX Health’s bottom-growth guide is a kind, clinically reviewed deep-dive.

Will T change my sexuality? Possibly, for some but it’s not predictable or universal. One survey found ~40% of trans men reported orientation shifts over their lives (partly attributed to T); a clinical cohort found no link between starting T and reported change. Libido (sex drive) increase is the well-documented constant. UCSF’s advice: explore new feelings rather than suppress them.176

Will T make me gain weight? It changes composition more than total weight: meta-analysis (a study pooling many studies) shows ~+1.7 kg total, +3.9 kg muscle, −2.6 kg fat, with fat redistributing toward the abdomen (belly).18 One adult cohort found no significant weight change at all.19 Appetite often increases; whether the scale moves depends on diet, activity, and genetics.

Does T raise libido forever? The common community framing is “libido goes up and stays up,” but the prospective (following people forward in time) ENIGI data show libido rising sharply by ~3 months and then returning toward baseline by 36 months for many people.20 Individual trajectories vary; both experiences are normal.

How long do I stay on T? As long as you want its maintained effects so realistically long-term/forever for most people. Permanent changes (voice, bottom growth, hair follicles, scalp loss) persist without it; maintained changes (no periods, fat/muscle pattern, libido) need ongoing T. If your ovaries are removed, you need some hormone for life. See FTM Long-Term Health.

Can I stop and restart? Yes! Pauses happen (pregnancy, supply issues, choice), and you’re not failing anyone by taking one. Reversible changes drift back while off; permanent ones stay. See FTM Low-Dose and Nonbinary for what reverts vs persists.

Further reading

No single website - this one included - should be your only source; these are reputable places to keep reading.

Related pages: FTM HRT | FTM Effects | FTM Risks and Side Effects | FTM Periods and Fertility | FTM Low-Dose and Nonbinary | FTM Community Knowledge | FTM Evidence Gaps

Footnotes

  1. Pope HG et al., Effects of Supraphysiologic Doses of Testosterone on Mood and Aggression, Arch Gen Psychiatry 2000 - https://jamanetwork.com/journals/jamapsychiatry/fullarticle/481565 ↩

  2. Kristensen TT et al., testosterone & aggression in transgender men: systematic review, Horm Behav 2021 - https://pubmed.ncbi.nlm.nih.gov/33309817/ ↩

  3. Huit TZ et al., anger/aggression/irritability after T initiation (12-month youth cohort), J Adolesc Health 2026 - https://pubmed.ncbi.nlm.nih.gov/41739008/ ↩

  4. “Just as Tall on Testosterone” - adult height in transgender boys, JCEM 2023 - https://pmc.ncbi.nlm.nih.gov/articles/PMC9844962/ ↩

  5. UCSF Transgender Care - Bone health and osteoporosis - https://transcare.ucsf.edu/guidelines/bone-health-and-osteoporosis ↩

  6. UCSF Transgender Care - Overview of masculinizing hormone therapy & patient document - https://transcare.ucsf.edu/guidelines/masculinizing-therapy ; https://transcare.ucsf.edu/article/information-testosterone-hormone-therapy ↩ ↩2 ↩3 ↩4

  7. Madsen MC et al., Testosterone in men with hypogonadism and transgender males (formulations review, 2022) - https://pmc.ncbi.nlm.nih.gov/articles/PMC9346330/ ↩

  8. Asseler JD et al., One-third of amenorrheic transmasculine people on testosterone ovulate, Cell Rep Med 2024 - https://pmc.ncbi.nlm.nih.gov/articles/PMC10982961/ ↩

  9. Endocrine Society Clinical Practice Guideline (Hembree et al., 2017) - https://academic.oup.com/jcem/article/102/11/3869/4157558 ↩

  10. Light AD et al., Transgender men who experienced pregnancy after transitioning, Obstet Gynecol 2014 - https://pubmed.ncbi.nlm.nih.gov/25415163/ ↩

  11. WPATH Standards of Care v8 (Coleman et al., 2022) - https://pmc.ncbi.nlm.nih.gov/articles/PMC9553112/ ↩ ↩2

  12. Tebbens et al., 3D facial scanning of hormone effects, J Clin Med 2019 - https://www.nve.nl/abstract/hormone-treatment-with-estrogen-and-testosterone-induces-facial-feminization-in-transwomen-and-masculinization-in-transmen-quantification-by-3d-scanning-and-patient-reported-outcome-measures/ ↩

  13. Stenton Mackenzie & Wilkinson, facial morphometric changes in FtM people (2017) - https://researchonline.ljmu.ac.uk/id/eprint/6283/1/FTM%20faces%20paper-accepted%20version-feb%2014.2017.pdf ↩

  14. Cleveland Clinic - Voice Masculinization (Deepening) - https://my.clevelandclinic.org/health/procedures/voice-masculinization-surgery ↩

  15. FOLX Health Library - Testosterone HRT and Bottom Growth (clinically reviewed) - https://www.folxhealth.com/library/testosterone-bottom-growth ↩

  16. Endocrine Society effects time-course table (2017) - https://nursing.ceconnection.com/ovidfiles/00006205-202203000-00004.pdf ↩

  17. Auer MK et al., Transgender Transitioning and Change of Self-Reported Sexual Orientation, PLoS ONE 2014 - https://pmc.ncbi.nlm.nih.gov/articles/PMC4192544/ ↩

  18. Klaver M et al., body composition meta-analysis, Andrologia 2017 - https://pubmed.ncbi.nlm.nih.gov/27572683/ ↩

  19. Korpaisarn S et al., effects of testosterone in transgender males, Arch Endocrinol Metab 2021 - https://pmc.ncbi.nlm.nih.gov/articles/PMC8511909/ ↩

  20. Defreyne J et al., sexual desire trajectory during gender-affirming hormone therapy (ENIGI), J Sex Med 2020 - https://pubmed.ncbi.nlm.nih.gov/32008926/ ↩

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