Cyclofenil
An older non-steroidal SERM historically used as an ovulation inducer and for menstrual disorders. It weakly antagonises oestrogen and raises gonadotropins, and has been used off-label as a milder PCT gonadotropin stimulant.
01 Overview
Cyclofenil (Sexovid, Fertodur) is a diphenylethylene-type SERM developed decades ago as a fertility agent for ovulation induction and management of menstrual irregularity. It is a relatively weak anti-estrogen compared with tamoxifen or clomifene.
In PED contexts it is sometimes used as a gentle HPTA-restart agent, blocking central oestrogen feedback to raise LH, FSH and testosterone with a comparatively mild side-effect profile, though modern clinical evidence is sparse.
02 Mechanism
Non-steroidal SERM: antagonises oestrogen negative feedback at the hypothalamus/pituitary, increasing gonadotropin secretion.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Off-label PCT | 200–400 mg/day | Oral | Anecdotal restart dosing; weak evidence. |
| Ovulation induction | 400–600 mg/day | Oral | Historic fertility dosing over several days. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Raised gonadotropinsCentral oestrogen antagonism stimulates pituitary output. | LH/FSH increase | Observational | |
| Ovulation inductionOriginal licensed fertility application. | Restored ovulation in anovulatory women | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Hot flashesVasomotor symptoms from oestrogen antagonism. | Mild | Common | Observational | |
| Hepatic enzyme elevationOccasional transaminase rises reported historically. | Moderate | Uncommon | Observational |