The Trans Directory

FTM Effects

7 min read

What changes on testosterone, how fast, and what stays if you stop? This page gives the official timeline from the Standards of Care, then enriches it with what studies and patients actually report - because the table is a population average and real lives are messier.

The effects timeline (WPATH SOC8)

Adapted from SOC8 (Appendix C), itself adapted from the Endocrine Society guideline.1

Remember these are based off observations from doctors and not actually a guaranteed timeline, everyone is different and most of the time the “maximum” time frame is quite wrong

EffectTypical onsetTime to maximumReversible if you stop T?
Skin oiliness / acne1-6 months1-2 yearsYes
Facial / body hair growth6-12 months (older guidance: 3-6)>5 yearsLargely no follicles stay
Scalp hair loss (male-pattern)6-12 months>5 years; variableNo (largely permanent; treatable)
Muscle mass / strength6-12 months2-5 yearsYes
Fat redistribution (hips/thighs to abdomen)1-6 months2-5 yearsYes
Periods stop (amenorrhea)1-6 months-Yes
Clitoral enlargement (“bottom growth”)1-6 months1-2 yearsNo (permanent)
Vaginal atrophy / dryness1-6 months1-2 yearsYes (and treatable while on T)
Voice deepening1-6 months (older guidance: 3-12)1-2 yearsNo (permanent)

Source: WPATH SOC8 Table 1 / Endocrine Society Table 12.12

What the research adds, effect by effect

Voice. The first signs are often a scratchy throat or hoarseness within weeks; the biggest pitch drop happens around 2-5 months, and most voices approach the cisgender male range by ~12 months (mean speaking frequency ~125 Hz in one longitudinal study - one that followed people over time).34 But not everyone gets there: a meta-analysis (a study pooling many earlier studies) of 520 trans men found ~21% still weren’t in the male-typical pitch range at 1 year, ~24% report voice symptoms (instability, fatigue), and full settling can take up to 2 years.53 Pitch didn’t track blood androgen (testosterone-family hormone) levels, so more T won’t force it. Voice work helps with pitch, resonance, and stamina, with or without T - see Voice Training.

Bottom growth (clitoral enlargement). Frequently the very first change people notice - within weeks - well ahead of the table’s 1-6 months.6 Typical size is around 1-4 cm; studies report up to 3.83-4.6 cm over 1-2 years.7 Early hypersensitivity or discomfort is common and usually settles by ~6 months. Considered permanent once it occurs.

Acne and skin. Oily skin and acne are among the earliest changes, and prevalence peaks around 4-6 months - 82% had facial acne and 88% chest/back acne at 6 months in one cohort - earlier than the table’s “1-2 year max” framing suggests. Long-term, ~94% have no or only mild acne.8 Standard acne care applies; severe cases deserve dermatology (see FTM Risks and Side Effects).

Periods. Most stop within 1-6 months: ~90% are amenorrheic (their periods have stopped) by 6 months and nearly all by 1 year at standard doses - which also means roughly 1 in 10 still bleeds at 6 months, and one prospective study (following people forward over time) found 16% still menstruating then.910 Periods often get lighter/later/shorter before stopping, and breakthrough bleeding can recur even years in (missed doses, dose changes). Persistent or returning bleeding is a titration signal - see FTM Periods and Fertility and FTM Dosages.

Facial and body hair. One of the slowest changes. Objective scores (Ferriman-Gallwey, a standard body-hair rating scale) climb from a median of 0.5 at baseline to 12 at 12 months, and keep climbing for a decade - but often stay below cisgender male density, and growth doesn’t correlate with blood T levels.8 Family pattern is the best predictor; starting later in life generally means less facial hair. Peach fuzz in the first months is common; a meaningful beard usually takes 2-5+ years.

Scalp hair loss. Follows male-pattern genetics: only ~5% notice loss in year one, but after ~10 years on T about two-thirds have some androgenetic alopecia (male-pattern hair loss) (33% mild, 31% moderate-to-severe in one long-term cohort).8 It’s “highly dependent on age and inheritance; may be minimal” per the guideline footnote. Minoxidil and finasteride exist as treatments, but finasteride stops your body converting T into DHT (the stronger hormone behind bottom growth and body hair) and can blunt those effects - a genuine trade-off to discuss first; the data conflict on how big the effect is.

Muscle and fat. In the first year: roughly +10% muscle mass and -10% fat mass in one DXA (body-composition X-ray) study; grip strength up ~18% by 12 months, most of it by 6 months.11 Fat gradually shifts from hips/thighs/buttocks toward the abdomen over ~2 years. Muscle gain is “significantly dependent on amount of exercise” (guideline footnote) - T lowers the effort required, it doesn’t replace it. Your chest changes little on T.

Libido and sexual changes. Sex drive commonly rises within the first weeks to 3 months. Long-term is honestly unclear: one large prospective study found desire rose by 3 months but drifted back toward baseline by 36 months, while most patient reports describe a sustained increase.12 Both findings are real; experience varies.

Body odor and sweat. Not in the official tables, but consistently among the first changes reported (weeks): sweat and urine odor change, and sweating increases.6

Vaginal/front-hole atrophy and dryness. Common (thinning, sometimes uncomfortable tissue) and treatable while staying on T - moisturizers, lubricants, and low-dose local estrogen are used, though the last has never been formally studied in trans people. See FTM Risks and Side Effects and FTM Evidence Gaps.13

What T won’t do. It won’t make you taller or change your bone structure once growth plates have fused (after puberty) - NHS guidance explicitly lists height and shoulder width among the things hormones can’t change14 - and it won’t remove breast tissue (that’s what top surgery is for). Facial masculinization in adults comes from fat redistribution and muscle, not bone, and takes 2+ years.

Footnotes

  1. WPATH Standards of Care v8 (Coleman E, et al., 2022), Appendix C, Table 1 - expected time course of physical changes - https://pmc.ncbi.nlm.nih.gov/articles/PMC9553112/ ↩ ↩2

  2. Endocrine Society Clinical Practice Guideline (Hembree WC, et al., 2017), Table 12; earlier-lineage timelines: Mayo Clinic, “Masculinizing hormone therapy” - https://academic.oup.com/jcem/article/102/11/3869/4157558 ; https://www.mayoclinic.org/tests-procedures/masculinizing-hormone-therapy/about/pac-20385099 ↩

  3. Nygren U, et al., “Effects on Voice Fundamental Frequency and Satisfaction with Voice in Trans Men during Testosterone Treatment,” J Voice 2016 - https://pubmed.ncbi.nlm.nih.gov/26678122/ ↩ ↩2

  4. Irwig MS, et al., “Effects of testosterone on the transgender male voice,” Andrology 2017 - https://onlinelibrary.wiley.com/doi/10.1111/andr.12278 ↩

  5. Ziegler A, et al. (2018) voice meta-analysis (520 trans men), summarized by Gender Analysis and SGUL review - https://genderanalysis.net/2021/02/trans-men-and-transmasculine-people-can-get-effective-vocal-pitch-surgery-too/ ↩

  6. Trans Research Australia (TRANSform), “Genital changes, periods, and pelvic pain” (2023); UCSF patient document - https://www.transresearch.org.au/post/pelvicpain ↩ ↩2

  7. Grimstad F, et al., “The role of androgens in clitorophallus development and anatomy,” Andrology 2021 - https://onlinelibrary.wiley.com/doi/full/10.1111/andr.13016 ↩

  8. Wierckx K, et al., “Short- and Long-Term Clinical Skin Effects of Testosterone Treatment in Trans Men,” J Sex Med 2014 - https://pubmed.ncbi.nlm.nih.gov/24344810/ ↩ ↩2 ↩3

  9. Rodrigues et al., review, Rev Bras Ginecol Obstet 2018 (amenorrhea ~90% at 6 months, ~100% at 1 year) - https://www.febrasgo.org.br/media/k2/attachments/revisedZupdateZRBGOZ40Z05ZfinalZproof.pdf ↩

  10. Deutsch MB, Bhakri V, Kubicek K., Obstet Gynecol 2015 (16% persistent menses at 6 months), quoted in the UCSF guideline - https://transcare.ucsf.edu/guidelines/masculinizing-therapy ↩

  11. Van Caenegem E, et al. (ENIGI), “Body composition in trans men,” Eur J Endocrinol 2015 - https://pubmed.ncbi.nlm.nih.gov/25550352/ ↩

  12. Defreyne J, et al. (ENIGI), “Sexual desire changes in transgender individuals,” J Sex Med 2020 - https://pubmed.ncbi.nlm.nih.gov/32008926/ ↩

  13. Tordoff DM, et al. (PRIDE Study), “Testosterone use and sexual function,” Am J Obstet Gynecol 2023 - https://pmc.ncbi.nlm.nih.gov/articles/PMC11182338/ ↩

  14. NHS, “Gender dysphoria - Treatment” - https://www.nhs.uk/conditions/gender-dysphoria/treatment/ ↩

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