Transdermal Estrogen (Patches & Gel)
Overview
Transdermal estradiol delivers estrogen through the skin directly into the bloodstream, completely bypassing first-pass liver metabolism. This makes it the safest route for VTE risk and the route preferred by clinical guidelines.
Available Forms
Estradiol Patches
| Brand | Strength | Frequency | Notes |
|---|---|---|---|
| Climara | 25–100 mcg/24h | Weekly | Large patch |
| Estradot | 25–100 mcg/24h | Twice weekly | Smaller patch |
| Evorel | 25–100 mcg/24h | Twice weekly | Common in UK/EU |
| Estraderm | 25–100 mcg/24h | Twice weekly | Reservoir patch |
Estradiol Gel
| Brand | Concentration | Typical Dose |
|---|---|---|
| Oestrogel | 0.06% (0.75 mg/pump) | 2–8 pumps/day |
| Sandrena | 0.5–1 mg/sachet | 1–3 sachets/day |
| Divigel | 0.25–1 mg/packet | 1–4 packets/day |
| Generic gel | Various | 1–5 mg/day |
How to Apply
Patches
- Clean and dry the application site (lower abdomen, buttocks, or upper thigh)
- Remove the protective liner
- Apply firmly for 10 seconds
- Rotate sites to prevent skin irritation
- Replace according to schedule (weekly or twice weekly)
Patch placement tips
- Apply to clean, dry, hairless skin
- Avoid the waistline (belt/friction can loosen)
- Rotate between left and right sides
- Do not apply to the same spot twice in a row
- If it falls off, apply a new patch and note the day
Gel
- Apply to clean, dry skin on shoulders, upper arms, or inner thighs
- Spread a thin layer over a large area
- Allow to dry for 3–5 minutes before dressing
- Wash hands thoroughly after application
- Do not wash the application area for at least 1 hour
Gel transfer warning
Estradiol gel can be transferred to others through skin contact. Once dry, cover the area with clothing. Avoid skin-to-skin contact with children, pregnant women, or partners at the application site until the gel is fully absorbed (30–60 minutes).
Dosing Guidelines
Patches
| Target | Dose |
|---|---|
| Starting | 50–100 mcg/24h |
| Typical | 100–200 mcg/24h |
| High | 200–300 mcg/24h |
| How to increase | Add more patches or switch to higher strength |
Gel
| Level | Pumps (Oestrogel) | Sandrena |
|---|---|---|
| Starting | 2–3 pumps/day | 1 mg/day |
| Typical | 4–6 pumps/day | 2 mg/day |
| High | 6–8 pumps/day | 3 mg/day |
Comparison: Patches vs Gel
| Aspect | Patches | Gel |
|---|---|---|
| Convenience | Apply twice weekly | Apply daily |
| Skin irritation | Common (rash, itching) | Rare |
| Level stability | Very steady | Steady with daily use |
| Dosing flexibility | Fixed strengths | Can fine-tune pump count |
| Transfer risk | Minimal (covered) | Higher (until dry) |
| Visibility | Visible on skin | Invisible when dry |
| Cost | Variable | Generally affordable |
Pros & Cons
| Pros | Cons |
|---|---|
| Lowest VTE risk of all routes | Skin irritation (patches) |
| Steady hormone levels | Must apply consistently |
| No needles | Absorption varies between people |
| Bypasses liver metabolism | Patches can fall off |
| Preferred by guidelines | Gel requires daily routine |
| Good for older patients | Some find it inconvenient |
Who Should Use Transdermal Estrogen
- People over 40 (lower VTE risk)
- Smokers (higher baseline VTE risk)
- Anyone with clotting risk factors
- Those who want the safest route long-term
- People who have had issues with other routes
References
Connelly PJ, et al. (2021). Managing the risk of venous thromboembolism in transgender adults undergoing hormone therapy. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC6628137/
Patel N, et al. (2024). Gender-affirming hormone therapy in the transgender patient: influence on thrombotic risk. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC11665511/
WPATH (2022). Standards of Care, Version 8. https://www.tandfonline.com/doi/full/10.1080/26895269.2022.2100644