The honest starting point: no clinical trial has shown that any supplement increases breast size. A review of "bust enhancing" herbal products in Obstetrics & Gynecology found that "no clinical trials have been published" and concluded that their use "should be discouraged because of lack of evidence for efficacy and long-term safety concerns".
- Red clover isoflavones: the most-studied ingredient here, but for menopause and breast density, not size. In a 12-month trial of 205 women, a red clover isoflavone tablet did not change mammographic breast density or hormone levels compared with placebo. A meta-analysis of 8 trials found no overall effect on breast density.
- Hops: contain 8-prenylnaringenin, a phytoestrogen described in the same review as more potent than other dietary phytoestrogens.
- Fenugreek, fennel, dong quai, saw palmetto: we found no human trials measuring breast size for any of them.
- The NCCIH says red clover and saw palmetto may be unsafe during pregnancy or breastfeeding.
- Phytoestrogen products are not a good idea for anyone with a history of hormone-sensitive cancer without their doctor's advice.
- Dong quai may interact with blood thinners such as warfarin.
- Promises of one or two cup sizes. The US Federal Trade Commission took action against the marketers of Bloussant, who claimed it increased breast size "by two cups in most women"; the settlement required $3.2 million in consumer redress.
- "Capsule plus cream" systems sold with before-and-after photos and no published study.
- Refund promises that differ from the written terms: check the terms page before buying.
We list what is on each label and what the evidence says, not a promise of results. If breast size or shape matters to you, a consultation with a doctor or a board-certified plastic surgeon will give you options that have actually been studied.
Sources: Fugh-Berman 2003, "Bust enhancing" herbal products · Atkinson et al. 2004, red clover and breast density · Hooper et al. 2010, isoflavones and breast density meta-analysis · NCCIH, red clover · FTC, Bloussant