Short-Term Side Effects
This page covers the common short-term side effects that may occur in the first weeks and months of feminising HRT. Most are temporary and manageable.
Common Side Effects
Breast Tenderness
| Details | Management |
|---|---|
| One of the first signs estrogen is working | Wear a soft, supportive bra or bralette |
| Usually begins within 2–4 weeks | Avoid sleeping on your stomach |
| Can be sharp or aching | Usually subsides after a few months |
| Normalises as breast development progresses | If pain is severe or one-sided, see a doctor |
Nausea
| Details | Management |
|---|---|
| Common with oral estrogen in first few weeks | Take with food |
| Usually resolves within 2–4 weeks | Try sublingual administration |
| Less common with transdermal/injectable | Ginger tea or anti-nausea meds if needed |
Fatigue / Low Energy
| Details | Management |
|---|---|
| Common in the first few weeks | Rest when needed |
| Body adjusting to new hormone balance | Ensure adequate sleep (7–9 hours) |
| Can be worse with CPA | Usually resolves within 1–2 months |
| Rule out anaemia (check CBC on blood test) |
Dizziness (Spironolactone)
| Details | Management |
|---|---|
| Due to blood pressure lowering effect | Take spiro with food |
| Most common in first 2 weeks | Stay hydrated — increase salt and water intake |
| Usually resolves as body adjusts | Stand up slowly from sitting/lying down |
| If persistent, ask provider about dose reduction |
Frequent Urination (Spironolactone)
| Details | Management |
|---|---|
| Expected — spiro is a diuretic | Take dose earlier in the day |
| Usually improves somewhat over time | Avoid taking close to bedtime |
| More noticeable at higher doses | Stay hydrated |
Hot Flashes
| Details | Management |
|---|---|
| Can occur when T is dropping quickly | Usually temporary (1–4 weeks) |
| Also seen with GnRH agonists | Ensure E2 is in adequate range |
| If persistent, check hormone levels |
Mood Changes
| Details | Management |
|---|---|
| Emotional lability is common early on | Give yourself grace — your brain is adapting |
| Can include crying more easily | Talk to supportive friends/community |
| Irritability or anxiety possible | If severe or persistent, talk to a therapist |
| If CPA is the cause, consider switching |
Less Common Short-Term Side Effects
| Side Effect | Likely Cause | What to Do |
|---|---|---|
| Headaches | Estrogen dose changes; blood pressure | Monitor; check BP; hydrate |
| Acne (temporary) | Hormonal fluctuation | Usually resolves; gentle skincare |
| Fluid retention / bloating | Estrogen effect | Reduce sodium; stay hydrated |
| Changes in body temperature regulation | Metabolic shift | Layer clothing; adjust thermostat |
| Changes in sense of smell | Hormonal | Generally harmless |
DVT / Pulmonary Embolism — Recognising the Signs
SEEK EMERGENCY CARE IMMEDIATELY IF YOU HAVE:
Leg (DVT):
- Swelling, pain, warmth, or redness — usually in one calf or thigh
Chest (PE):
- Sudden shortness of breath, sharp chest pain (worse when breathing deeply), coughing up blood
Heart / Circulation:
- Rapid pulse, lightheadedness, feeling faint
These are signs of deep vein thrombosis (DVT) or pulmonary embolism (PE). Do not wait — go to the emergency room.
When to Seek Medical Attention
Emergency warning signs
Seek immediate medical attention if you experience:
- Sudden shortness of breath — could be pulmonary embolism (PE)
- Chest pain — could be PE or heart-related
- Leg pain/swelling/redness (especially one leg) — could be deep vein thrombosis (DVT)
- Sudden severe headache — could be stroke or meningioma-related
- Vision changes — double vision, blurring — could be meningioma (CPA-related)
- Severe depression or suicidal thoughts — seek mental health crisis support
- Signs of allergic reaction — rash, swelling, difficulty breathing (rare)
Side Effects Checklist (First 3 Months)
| Week | What to Expect |
|---|---|
| Week 1–2 | Nausea (pills), dizziness (spiro), frequent urination |
| Week 2–4 | Breast tenderness begins; mood changes; skin softening |
| Week 4–8 | Fatigue improving; libido decreasing; reduced erections |
| Month 2–3 | Most short-term side effects stabilise or resolve |
References
Hembree WC, et al. (2017). Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons. JCEM. https://academic.oup.com/jcem/article/102/11/3869/4157558
Deutsch MB, ed. (2016). Guidelines for the Primary and Gender-Affirming Care of Transgender and Gender Nonbinary People. UCSF Transgender Care. https://transcare.ucsf.edu/guidelines