What is HRT? (Trans Male Guide)

HRT stands for Hormone Replacement Therapy. For trans males, it is a medical treatment that helps align your physical characteristics with your gender identity through the use of testosterone.

How HRT Works

Masculinising hormone therapy (GAHT) for trans men typically involves:

1. Introducing testosterone — Taking testosterone to raise levels into the cisgender male range
2. Suppressing estrogen — Testosterone naturally suppresses estrogen production through HPG axis feedback
3. Monitoring for side effects — Regular blood tests to manage hematocrit, lipids, and other markers

Testosterone therapy induces male-puberty-like changes: voice deepening, facial and body hair growth, fat redistribution, muscle mass increase, and cessation of menstruation.

What HRT Does (and Doesn't) Do

Physical Changes

Timelines are highly individual

The ranges below are population-level observations, not predictions for any one person. Onset and progression depend heavily on your regimen, dosage, age, genetics, and overall health.

Change	Typical Onset	Typical Peak	Reversible?
Voice deepening	3–6 months	1–2 years	No
Facial/body hair growth	3–6 months	3–5 years	No (partially)
Menstrual cessation	2–6 months	6–12 months	Yes (returns if T stops)
Clitoral growth (bottom growth)	1–3 months	1–2 years	No
Fat redistribution	3–6 months	2–5 years	Yes
Muscle mass increase	3–6 months	2–3 years	Yes
Skin oiliness/acne	1–3 months	1–2 years	Yes
Body odour change	1–3 months	3–6 months	Yes
Scalp hair loss (male pattern)	6–12 months	2–5 years	Partially
Increased libido	1–3 months	3–6 months	Yes

Fertility Warning

Masculinising HRT will likely reduce your fertility, but the effect varies. HRT is not a contraceptive — use a reliable method of birth control if relevant to you.

Gamete Storage

If you are considering having biological children in the future, discuss egg/ovarian tissue storage with a healthcare provider before starting HRT.

What HRT Does NOT Do

• Change your bone structure — height, hand/foot size, and hip width are unchanged
• Remove breast tissue — testosterone does not significantly reduce breast size; top surgery is required
• Guarantee fertility preservation — HRT reduces fertility; permanent infertility is possible
• Guarantee voice drop — the extent of voice deepening varies

Key Hormone Targets & Monitoring

For masculinising GAHT, the Endocrine Society and WPATH SOC8 recommend targeting:

• Testosterone (T) — in the cisgender male range, typically 300–1,000 ng/dL
• Estradiol (E2) — should be suppressed, ideally below 50 pg/mL
• Hematocrit (HCT) — must stay below 54% (risk of polycythemia)

The Endocrine Society recommends monitoring hormone levels every 3 months during the first year of therapy.

Common Medications for Masculinising HRT

Testosterone Options

Form	Examples	Typical Dose	Notes
Injections (IM/SC)	Testosterone cypionate, enanthate	50–100 mg/week or 100–200 mg/every 2 weeks	Most common; steady levels with weekly dosing
Gel/cream	AndroGel, Testogel	25–100 mg/day	Good for stable levels; transfer risk to others
Patches	Androderm	2–6 mg/day	Can cause skin irritation
Pellets (implants)	Testopel	750–1,500 mg every 3–6 months	Long-lasting; requires insertion procedure
Buccal tablets	Striant	30 mg twice daily	Adheres to gum; least common

Estrogen Blockers (Aromatase Inhibitors)

Medication	Typical Dose	Notes
Anastrozole	1 mg/week	Used if E2 is elevated despite adequate T
Letrozole	2.5 mg/week	Alternative to anastrozole

Progestins (for Bleeding Control)

Medication	Typical Dose	Notes
Norethindrone	5 mg/day	Short-term option for persistent bleeding
Medroxyprogesterone acetate	10 mg/day	Alternative option

Side Effects & Risks

Polycythemia (High Red Blood Cell Count)

The most common significant side effect of testosterone therapy. Testosterone stimulates erythropoietin, increasing red blood cell production.

HCT Level	Risk	Action
< 50%	Normal	Routine monitoring
50–54%	Moderate	Monitor; consider blood donation
> 54%	High	Reduce T dose or therapeutic phlebotomy

Other Side Effects

• Acne — very common, especially in first 1–2 years
• Male pattern balding — genetic predisposition determines extent
• Sleep apnoea — testosterone may worsen pre-existing sleep apnoea
• Lipid changes — T can lower HDL and raise LDL
• Increased libido — expected and usually welcome
• Mood changes — irritability or aggression (dose-dependent)
• Weight gain — mostly lean muscle mass

DIY vs Prescribed HRT

Prescribed HRT

• Under supervision of an endocrinologist or knowledgeable provider
• Regular blood tests and dose adjustments
• Pros: safer, medically supervised, legal protection
• Cons: long waiting lists, gatekeeping, cost

DIY HRT

• Obtaining testosterone without a prescription
• Pros: immediate access, full control
• Cons: requires self-education, blood testing, reputable sourcing; testosterone is a controlled substance in most countries

If you use DIY HRT, you must:

1. Test your blood regularly — every 3 months during the first year
2. Source from reputable vendors — see the Sources section
3. Educate yourself thoroughly — understand dosing, side effects, and emergency signs
4. Be aware of legal risks — testosterone is a controlled substance in many jurisdictions

Is HRT Reversible?

Some effects are permanent:

• Voice deepening — permanent
• Bottom growth — permanent
• Facial/body hair — permanent but may thin if T stops
• Male pattern baldness — permanent (hair loss reversal unlikely)

Most other changes reverse if HRT is stopped:

• Fat redistribution, muscle mass, skin changes, menstruation return, and fertility generally reverse over time

References

1. Hembree WC, et al. (2017). Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons. JCEM. https://academic.oup.com/jcem/article/102/11/3869/4157558

2. WPATH (2022). Standards of Care, Version 8. https://www.tandfonline.com/doi/full/10.1080/26895269.2022.2100644

3. UCSF Transgender Care. Guidelines for the Primary and Gender-Affirming Care of Transgender and Gender Nonbinary People. https://transcare.ucsf.edu/guidelines