How the Process Works: Informed Consent

There are two established models for initiating gender-affirming hormone therapy (GAHT). The traditional model requires evaluation and a letter from a mental health professional confirming gender dysphoria before hormones can be prescribed. The informed consent model — which has become increasingly accepted and is supported by the American College of Obstetricians and Gynecologists — allows a clinician to initiate therapy after a thorough informed consent process, without requiring a separate mental health letter.[1]

In my practice, I use the informed consent model for adults. What that process involves is not a shortcut — it's a substantive conversation that covers the expected physical changes, what is reversible and what isn't, fertility implications, monitoring requirements, and the risks associated with therapy. I do ask that patients have had persistent feelings of gender incongruence for at least a year before starting, to ensure we're not acting on something transient. The goal is a fully informed patient who has had the time and space to think through a decision with real and lasting consequences.

📊 The Evidence — Informed Consent Model ACOG states that an informed consent process without a separate letter from a mental health professional is more than adequate for initiating hormone therapy in adults who wish to medically transition, provided the clinician confirms persistent gender dysphoria or incongruence, assesses capacity to consent, thoroughly discusses risks and expected changes, addresses fertility, and ensures any significant coexisting medical or mental health conditions are reasonably well controlled.[1] The Endocrine Society guidelines recommend involvement of a mental health professional but acknowledge that the role can be fulfilled within a well-structured primary care relationship.[2]

What About Surgery?

Hormone therapy and surgery are separate decisions with different timelines. I generally recommend approximately 12 months of hormone therapy before considering surgical referral — not as a gatekeeping requirement, but because that period allows the body to adapt, gives patients lived experience with the physical changes testosterone produces, and helps clarify which surgical interventions, if any, are right for them. Surgical referral standards typically require documentation from mental health professionals, and genital surgery usually requires 12 months of hormone therapy and 12 months of living in the affirmed gender role.[2]

Fertility: The Conversation That Must Come First

I consider fertility counseling non-negotiable before starting testosterone, regardless of a patient's age, stated plans, or certainty about their reproductive future. This isn't a value judgment about whether someone should want biological children — it's about making sure the option remains available if they ever do.

Testosterone causes a reduction in fertility that may be temporary or permanent. Menstrual cycles typically stop within the first few months of therapy, but cessation of periods does not mean cessation of ovulation — pregnancy remains possible on testosterone, and contraception should be discussed for anyone with a uterus who has any possibility of pregnancy.[3] For patients who want to preserve future fertility options, oocyte or embryo cryopreservation before starting therapy is the most reliable approach, and that conversation is easier to have before therapy begins than after.

⚠ Important: Testosterone Is Not Contraception The absence of periods on testosterone does not mean pregnancy is impossible. Ovulation can still occur, and pregnancies have been documented in trans men on testosterone therapy. Anyone with a uterus and any chance of pregnancy should discuss contraception before starting and during therapy.[3][4]

What to Expect: The Physical Changes

The physical changes from testosterone happen gradually over months to years. Some are expected effects of masculinization — not side effects — and it's important to frame them that way. Understanding the timeline and which changes are permanent helps patients make a fully informed decision.

1–3 months

Early changes

  • Increased sexual desire
  • Skin becomes oilier; acne may develop
  • Clitoral enlargement (clitoromegaly) begins
  • Vaginal dryness and atrophy begin — lubricant or low-dose vaginal estrogen may help
  • Increased body and facial hair growth begins
3–6 months

Menstrual changes and body composition

  • Menstrual periods typically stop (usually within 3–6 months)
  • Fat redistribution toward abdomen and away from hips and thighs
  • Increased muscle mass and strength
  • Continued facial and body hair growth
6–12 months

Voice and hair changes

  • Voice deepening begins — this is gradual and permanent. Testosterone lowers the voice, but achieving a fully masculine-sounding voice almost always requires speech therapy in addition to hormone therapy — pitch is only one component of how gender is communicated vocally, and a trained voice therapist can work on resonance, intonation, and projection in ways testosterone alone does not address.
  • Male-pattern scalp hair thinning may begin in those with genetic predisposition — partially or fully irreversible
1–5 years

Slower ongoing changes

  • Continued beard and body hair development (may take 3–5 years to reach full effect)
  • Further voice stabilization
  • Clitoral growth continues, then stabilizes
  • Bone density changes stabilize

Reversibility — What Stops When Testosterone Stops

Change Reversibility
Menstrual cessation Reversible — periods typically return after stopping
Skin oiliness and acne Reversible
Increased libido Reversible
Fat redistribution Partially reversible
Muscle mass increase Partially reversible
Clitoral enlargement Partially reversible — some regression but usually not complete
Facial and body hair Irreversible — hair does not disappear after stopping
Voice deepening Irreversible — the voice does not return to prior pitch
Scalp hair loss Largely irreversible — may not regrow after stopping
Fertility reduction Uncertain — may recover after stopping, but not guaranteed

Formulations and Dosing

The goal of testosterone therapy for masculinization is to achieve levels in the normal male physiologic range — I target approximately 350 to 750 ng/dL, which sits in the mid-normal male range and minimizes the risk of erythrocytosis compared to pushing toward the upper end of normal.[2][4] Testosterone cypionate injection is often a practical first choice given its low cost and flexibility, though transdermal gels are a reasonable alternative for patients who prefer to avoid injections.

Dosing is started low and titrated upward based on clinical response and measured testosterone levels. The target is mid-normal male range, not the upper end — higher levels don't produce faster or more complete masculinization, and they do increase the risk of erythrocytosis and other adverse effects.

Monitoring: What Gets Checked and Why

Regular monitoring during the first year is more frequent than in later years, reflecting the period of active dose adjustment and the highest risk of hematocrit elevation.

⚠ Monitoring Schedule
  • Every 3 months in year one: Testosterone level, hematocrit/hemoglobin, clinical assessment of masculinizing effects and side effects
  • 1–2 times yearly thereafter: Same parameters plus weight, blood pressure, and lipids
  • Target testosterone: 350–750 ng/dL — mid-normal male range, chosen to balance masculinizing effect with lower erythrocytosis risk
  • Hematocrit above 54%: Dose reduction or temporary hold required — blood donation is a practical option to manage rising counts (see Post 2.2)

Health Risks to Monitor

Erythrocytosis

The most important adverse effect requiring active monitoring is an elevated hematocrit (erythrocytosis) — the same risk that applies to testosterone in cisgender men, covered in detail in Post 2.2. It's particularly relevant in patients with sleep apnea, which is both a risk factor for erythrocytosis and a condition that testosterone can worsen.[2]

Cardiovascular and Metabolic Effects

Testosterone therapy produces an atherogenic lipid profile — lower HDL cholesterol (the "good" kind) and higher triglycerides and LDL. Despite these changes, long-term studies from the Netherlands have not found an increased risk of cardiovascular mortality in transgender men on testosterone.[2] This is reassuring, though cardiovascular monitoring — blood pressure and lipids — remains part of routine annual care.

Vaginal Atrophy

Testosterone causes vaginal atrophy — thinning and drying of vaginal tissue — which can cause discomfort, particularly for patients who are sexually active or require pelvic exams. Low-dose vaginal estrogen addresses this effectively without meaningfully affecting masculinization or systemic estrogen levels, and it's a conversation worth having early in treatment.[4]

Cancer Screening

Routine cancer screening should continue based on the organs each patient has, regardless of gender identity or hormone status. Trans men with a cervix need cervical cancer screening. Those with breast tissue — who have not had chest surgery — need breast cancer screening per standard guidelines. Testosterone does not eliminate these needs, and affirming care includes making sure patients feel comfortable accessing them.

My Synthesis Gender-affirming testosterone therapy is one of the areas of my practice where the evidence on benefit is clearest and most consistent. Studies show meaningful improvements in quality of life, mental health, and gender congruence in patients who receive appropriate hormone therapy — and withholding or delaying treatment has documented harms of its own. My approach is informed consent, not gatekeeping. A patient who has thought carefully about this decision, understands what is reversible and what isn't, has addressed fertility, and has no major contraindications is ready to start.

The fertility conversation is the one I take most seriously, because it is the one with the most irreversible potential consequences. I have it with every patient, regardless of age or stated plans. Someone who is 22 and certain they never want children may feel differently at 35 — and I'd rather spend time on that conversation now than have a patient wish we had.