Estradiol Implants (Pellets)
Overview
Estradiol implants (also called pellets) are small, solid cylinders of crystalline estradiol that are inserted subcutaneously (under the skin), typically in the buttock or lower abdomen. They provide sustained release of estradiol for 3–12 months, making them the longest-lasting form of estrogen replacement.
How It Works
The implant is placed under the skin via a minor procedure (local anaesthetic, small incision). The body slowly absorbs the estradiol from the implant over months. Absorption rates vary by individual.
| Brand | Strength | Duration |
|---|---|---|
| Estradiol implant (compounded) | 25–100 mg | 3–12 months |
| Estradiol implant (commercial) | 50 mg | 6–8 months (typical) |
Availability
- Common in: Australia, UK (private), New Zealand
- Limited in: United States (compounding pharmacies can make them; not widely prescribed)
- DIY availability: Very limited — requires medical insertion
Implants are NOT suitable for DIY HRT
Estradiol implants require a medical procedure (incision under local anaesthetic) for insertion and sometimes removal. Attempting to insert or remove implants yourself carries serious risks including infection, improper placement, bleeding, and the inability to remove the implant if levels are too high. Implants are mentioned on this page for completeness only.
Pros & Cons
| Pros | Cons |
|---|---|
| Set-and-forget for months | Requires medical insertion |
| Very stable estradiol levels | Can be difficult to remove |
| No daily maintenance | Peak levels can be very high initially |
| Low VTE risk | Duration varies unpredictably |
| Excellent for T suppression | Removal may be needed if levels too high |
Who Should Consider Implants
- People who want the longest interval between doses
- People who've had stable levels on other routes
- Those who have access to a provider who offers implants
References
Garnett T, et al. (2020). Estradiol implants in transgender women. Australian Journal of General Practice.
UCSF Transgender Care. Estrogen: routes of administration. https://transcare.ucsf.edu/guidelines