Gestrinone vs Anavar: Which Is Harder on a Woman's Labs?

Gestrinone and oxandrolone come up together because Brazilian compounding pharmacies often put them in the same hormone implant, sometimes with testosterone, and Anvisa named both as the main hormones in compounded implants.

Gestrinone is a 19-nortestosterone derivative, the nandrolone family. It was developed for endometriosis at 2.5 mg orally twice a week. It is androgenic, antiprogestogenic and antiestrogenic, so it shrinks endometriosis lesions and usually stops periods. It is the parent compound of the designer steroid THG.

Oxandrolone (Anavar) is a 17-alpha-alkylated DHT derivative taken orally. It was developed for weight gain after surgery, trauma and burns, and it is the steroid women most often use for body composition.

Neither has been studied in healthy women who train, and they have never been compared directly.

What each was built for:

• Gestrinone: endometriosis. Suppresses estrogen and progesterone signalling in endometrial tissue
• Oxandrolone: anabolic support in muscle wasting, burns and recovery

Periods and estrogen:

• Gestrinone: stopped periods in about 41% of reports in a 2025 safety review and keeps estradiol low. That is the point of it for endometriosis
• Oxandrolone: often causes missed periods at 10-20 mg/day through HPG suppression, but it is not designed to

HDL:

• Gestrinone: down 25-41% over 6 months in endometriosis trials, with LDL and ApoB up in most
• Oxandrolone: down 20-45% at 10-20 mg/day in women, ApoB up

SHBG:

• Gestrinone: 56.4 to 7.1 nmol/L by week 4 in one study, roughly 87% down
• Oxandrolone: 70-90% down at 10-20 mg/day

Liver:

• Gestrinone: not 17-alpha-alkylated. Raised transaminases in 15.1% of pooled reports
• Oxandrolone: 17-alpha-alkylated. ALT commonly rises 1.5-3 times the upper limit at female doses

Virilisation:

• Both cause acne, oily skin, hirsutism and voice change. Gestrinone caused more hirsutism than danazol in the Cochrane data (odds ratio 2.63)

How it's taken:

• Gestrinone: oral twice weekly, or an implant that releases for months and can only be stopped by removal
• Oxandrolone: oral daily, short half-life, stops within days of the last dose

Gestrinone has a medical case only for endometriosis, and even there modern options such as dienogest, the combined pill and GnRH-based drugs have stronger evidence and fewer androgenic effects.

Oxandrolone has medical uses in muscle wasting and burns. Its use for body composition in healthy women is off-label.

For body composition, neither is a good choice. There is no evidence gestrinone helps fat loss, lipedema or body shape, and about 40% of endometriosis studies reported weight gain.

If you already have a combined implant, test a lipid panel with ApoB, SHBG with free testosterone, ALT and a full blood count at 6-8 weeks. You can't tell which drug is causing what, so judge the implant as a whole.