Consumer test to evaluate the efficacy of SoyLife isoflavones on reducing hot flashes felt by menopausal women

Frutarom, by Aster Céphac, France, June 2000

A number of studies suggest that the combination of soy isoflavones with natural vitamin E from soy may have a beneficial effect on the reduction of hot flashes. To test this, a study was designed to measure the beneficial effects of SoyLife EXTRA in the reduction of hot flashes. SoyLife EXTRA is a unique soy ingredient in that it contains a high concentration of isoflavones as well as natural vitamin E from soy.

Study design

Eighty menopausal women were selected from the Paris area (France). All exhibited an intermediate level of hot flashes. These women represented a part of the population that would generally not visit a medical practitioner for these types of symptoms, but would rather consider alternative medication. The group was randomized and treated with 2 capsules per day with either casein (as a placebo), or 20 mg isoflavones (as aglycones) per capsule. Capsules were taken with breakfast and dinner. Each patient recorded her number of hot flashes for a full week at week 0 (prior to treatment), at week 4 and at week 8. The women also categorized their hot flashes as severe, moderate or light hot flashes.

Results and conclusion

The reduction in number of hot flashes counted per week is shown in the graph. Forty mg of isoflavones from SoyLife significantly reduced the number of hot flashes in menopausal women. After 2 months, the effect of SoyLife was significantly larger than placebo. The existence of placebo effects in clinical evaluations of menopausal symptoms is generally accepted to be as much as 30%, and was confirmed in this study. Placebo effects are known to disappear over time, with symptoms ultimately returning at the initial severity.

In addition to decreasing the total number of hot flashes, SoyLife also reduced the average severity of hot flashes. The number of severe hot flashes decreased significantly faster than the number of light hot flashes.


For menopausal women, SoyLife EXTRA was shown to be an effective natural aid to deal with menopause. The study shows that not only the total number of hot flashes decreases while consuming isoflavones, but that the average severity of hot flashes reduces as well. Categorizing the severity of hot flashes for each woman, the share of severe hot flashes drops significantly faster than the share of light hot flashes. This further improves the quality of life during menopause.