Life Extension Estrogen For Women

Soy isoflavones· evidence: Limited

Soy isoflavones (genistein, daidzein and glycitein) are plant compounds with a weak oestrogen-like structure. They are widely studied in women around the menopause.

Reviews, including a Cochrane review, find that some trials show small differences compared with placebo and others show none, so the overall picture is inconsistent. There are no authorised health claims for soy isoflavones, so we make no claims about what they do. If menopause symptoms are affecting you, your GP can talk you through options with stronger evidence.

EFSA's 2015 safety assessment found no evidence of harm to the breast, uterus or thyroid in healthy post-menopausal women taking 35 to 150 mg a day for the periods studied.

Typical dose: Products typically give 40 to 100 mg of isoflavones a day.

Safety: Contains soy. Do not use if you have had breast cancer or another hormone-sensitive condition, unless your specialist agrees. Soy can reduce the absorption of levothyroxine, so take them at different times and tell your GP. Not for use in pregnancy, breastfeeding or by children. Speak to your GP if you take HRT, tamoxifen or blood thinners.

Research we looked at:
EFSA ANS Panel (2015). Risk assessment for peri- and post-menopausal women taking food supplements containing isolated isoflavones. EFSA Journal 13(10):4246.
Lethaby A et al. (2013). Phytoestrogens for menopausal vasomotor symptoms. Cochrane Database of Systematic Reviews, CD001395.
NICE (2015, updated 2024). Menopause: diagnosis and management (NG23).

Chasteberry (Vitex agnus-castus)· evidence: Limited

Chasteberry is the fruit of the chaste tree. It is thought to act on the hormone prolactin, and it is one of the few herbs with several controlled trials in women, mostly looking at premenstrual symptoms. Results are positive in some trials, but many are small or of mixed quality.

In the UK some chasteberry products are registered as traditional herbal medicines, which is a different route from food supplements. As a food supplement it has no authorised health claims, so we make no claims about what it does. If cycle-related symptoms are affecting your life, speak to your GP.

Typical dose: Studies commonly used 4 to 40 mg a day of a dried fruit extract; check the extract ratio on the label.

Safety: May interact with hormonal contraception, HRT and fertility treatment, and with dopamine-related medicines (for example some Parkinson's and antipsychotic medicines). Do not use in pregnancy or breastfeeding, or if you have a hormone-sensitive condition. Speak to your GP first if you take any of these medicines. Side effects can include headache, nausea and skin rash.

Research we looked at:
European Medicines Agency (HMPC). European Union herbal monograph on Vitex agnus-castus L., fructus.
van Die MD, Burger HG, Teede HJ, Bone KM (2013). Vitex agnus-castus extracts for female reproductive disorders: a systematic review of clinical trials. Planta Medica 79(7):562-575.

Dong quai (Angelica sinensis)· evidence: Insufficient

Dong quai is a root used in traditional Chinese medicine, often in formulas for women. There are very few good-quality human trials of dong quai taken on its own, and those that exist have not shown a clear effect.

There are no authorised health claims for dong quai, so we make no claims about what it does.

Typical dose: Products typically give 500 to 1,500 mg of root or extract a day.

Safety: Dong quai can increase the effect of warfarin and other blood thinners and has been linked to bleeding; stop before surgery. It contains compounds that can make skin more sensitive to sunlight. Do not use in pregnancy or breastfeeding, or if you have a hormone-sensitive condition. Speak to your GP or pharmacist first if you take regular medication.

Research we looked at:
NCCIH. Dong Quai. National Institutes of Health.
Page RL, Lawrence JD (1999). Potentiation of warfarin by dong quai. Pharmacotherapy 19(7):870-876.

Cost per daily dose lets you compare packs of different sizes fairly.Worked out from our current prices.