Vitamin E for Vaginal Dryness

Vitamin E used inside the vagina has early, mostly positive evidence for vaginal dryness after menopause; vitamin E swallowed as a supplement has none. A 2022 systematic review found four small randomised trials: vaginal vitamin E beat placebo in one 8-week trial of 42 women, and two 12-week reports of 52 women, probably the same trial, found no significant difference from estrogen cream (Porterfield 2022).

That is a thin base. The trials are small and short, use doses from 1 mg to 500 mg, and the two estrogen comparisons appear to come from the same group of women. In the one head-to-head trial, vaginal hyaluronic acid did significantly better (Porterfield 2022). Guidelines still start with moisturisers and lubricants, and turn to vaginal estrogen, vaginal DHEA or ospemifene for moderate to severe symptoms (NAMS 2020).

The trials measured effects rather than explaining them. In postmenopausal women, 100 IU vitamin E suppositories raised the vaginal maturation value (a score of how many surface cells the thinned lining is producing) from about 44 to 81 over 12 weeks (Parnan Emamverdikhan 2016). In women on tamoxifen, vitamin E suppositories raised the maturation index and lowered vaginal pH more than placebo (Keshavarzi 2019). A small retrospective, uncontrolled study also reported fewer E. coli after two weeks of 500 mg tocopherol acetate ovules (Venditti 2024).

Why vitamin E would do this is not established. One trial team pointed to a role in estrogen stability (Parnan Emamverdikhan 2016), which has not been tested in vaginal tissue. Because vitamin E beat a placebo suppository in the tamoxifen trial, the benefit is probably not just the moisture of the suppository itself, though the abstract doesn't describe the placebo (Keshavarzi 2019).

No trial has given vitamin E by mouth for vaginal dryness, so there is no evidence that swallowed vitamin E reaches vaginal tissue in a useful amount. Oral vitamin E's menopause trials looked at hot flushes instead, and even there vitamin E alone did not reduce their frequency more than placebo (Maghalian 2022). The local results on this page don't carry over to capsules.

Every positive trial used a vaginal product, taken at bedtime in the tamoxifen trial (Keshavarzi 2019). Doses varied widely: 1 mg in a placebo-controlled trial, 100 IU in the two estrogen comparisons (Porterfield 2022) and 500 mg tocopherol acetate ovules in a retrospective, uncontrolled study (Venditti 2024). No trial compared doses, so there is no evidence that more works better.

Trials lasted 8-12 weeks. Cell markers had already improved by week 4 in one trial, but estrogen cream got there faster (Parnan Emamverdikhan 2016). Give it 8-12 weeks before judging it.

A research group in Mashhad, Iran, randomised 52 postmenopausal women to 100 IU vitamin E suppositories or 0.5 g conjugated estrogen cream for 12 weeks. The vaginal maturation value rose in both groups (P < 0.001), from 43.78 to 80.59 with vitamin E and from 42.86 to 91.57 with estrogen. At 4 weeks, 76.9% of the vitamin E group met the success threshold versus 100% with estrogen (P = 0.01) (Parnan Emamverdikhan 2016).

The same team reported sexual function in 52 women over the same years: scores improved in both groups (P < 0.001), with no significant difference between them (Golmakani 2019). These look like two reports of one trial, and 52 women are too few to prove vitamin E equals estrogen. A double-blind trial of a combined vitamin D and E cream in 64 women also found no difference from estrogen cream for dryness, burning, itching and painful sex (Radnia 2023), but it can't show what vitamin E adds on its own.

In one 8-week trial of 42 postmenopausal women, 1 mg vaginal vitamin E reduced vaginal symptoms more than placebo (difference in means 5.3, 95% CI 4.4 to 6.2) (Porterfield 2022).

The best-designed trial was in women with breast cancer taking tamoxifen, who cannot use hormone therapy. In a triple-blind design, 96 women used nightly vitamin E, vitamin D or placebo suppositories for 8 weeks. Both vitamins improved self-reported atrophy symptoms, raised the maturation index and lowered vaginal pH compared with placebo (all P < 0.001) (Keshavarzi 2019). The abstract does not give the doses or the size of the improvement.

In the only head-to-head trial with another non-hormonal option, 5 mg vaginal hyaluronic acid eased symptoms more than 1 mg vitamin E in 40 women (difference -0.50, 95% CI -0.95 to -0.05) (Porterfield 2022). A broader 2022 review of 55 trials of treatments for vaginal atrophy and sexual problems after menopause found only one vitamin E trial, against 18 for lubricants and moisturisers (Sarmento 2022).

After pelvic radiotherapy, a review found tocopherol acetate reduced vaginal inflammation, but most of the evidence was for products combining vitamin E with hyaluronic acid and vitamin A (Wierzbicka 2021). A retrospective study of 50 women (22 of them premenopausal) reported dryness resolved after two weeks of 500 mg ovules, but it had no control group (Venditti 2024). The 2022 review called for better trials to settle efficacy, dosing and long-term safety (Porterfield 2022); no trial so far has lasted longer than 12 weeks.

The vaginal trials were short and their abstracts report little on side effects; the 2022 review called long-term safety unknown (Porterfield 2022). The bigger documented risks belong to high-dose oral vitamin E, which is not the route with evidence here. In one meta-analysis, the 11 trials of 400 IU a day or more showed 39 extra deaths per 10,000 people (95% CI 3 to 74), mostly in people with chronic disease (Miller 2005); in another, oral vitamin E raised haemorrhagic stroke risk by 22% across the five trials that reported it (Schürks 2010).

Dryness has many causes besides low estrogen, including infections and skin conditions, and some need different treatment. Guidelines note that the safety of vaginal estrogen and DHEA after breast cancer is not settled and that care should follow the oncologist's advice (NAMS 2020).

How much vitamin E is absorbed from a vaginal suppository has not been measured in these trials, so interaction data come from oral use. In a small double-blind trial of 21 people on warfarin, oral vitamin E did not change INR (Kim 1996), but in 566 people on warfarin, higher blood vitamin E levels predicted bleeding (Pastori 2013).