The first time that I came across black cohosh was in KaplanMD's Perfecting Serum ($185). I soon realized that Dr K is so enamored of this botanical that he puts it in just about every product in his range. It has been on my mind to find out more about it and so I did although I ended up not much wiser. Black cohosh comes with no research, bad research or contradictory research.

Black cohosh is a member of the buttercup family and native to North America. Other common names include black snakeroot, bugbane or bugwort on account of the fact that insects avoid it.

Early American physicians used black cohosh for female reproductive problems, including menstrual cramps and bleeding irregularities, as well as uterine and ovarian pain. Since the 1950s, it has been a popular alternative remedy for symptoms of menapause, primarily hot flashes. The association with menopause was made because black cohosh is considered to be a pro-estrogen, meaning that its constituents bind to estrogen receptors in the body. In fact, one compound in particular was recently identified in black cohosh (fukinolic acid) that was shown to have estrogenic activity in vitro. The other active is triterpene glycosides, a saponin that is also found in ginseng.

However, recent studies suggest that there is no real evidence that it works any better than a placebo. According to the National Institutes of Health, research conducted so far is contradictory and there was "a lack of rigor in study design and short study duration (6 months or less)".

There are several doctors and researchers that say that estrogen mimicking ingredients can also lead to cancer. When we put this to Dr Kaplan, his response was: "As far as estrogens mimicking ingredients, I totally disagree- there are people that specialize in cancer research that disagree, there’s no way that this product would be recommended among breast cancer patients and by oncologists. Black cohosh and soy are perfectly safe topically."

According to the National Institutes of Health's Office of Dietary Supplements, studies of black cohosh and cancer have given contradictory results. In some research, black cohosh seemed to trigger small increases in the number of cancerous cells, while other research showed a decrease in cancer cells when people used black cohosh. More research is needed.

Anyway, black cohosh may not even behave like estrogen after all, according to the National Institutes of Health citing "research" that it - frustratingly and unforgivably - does not reference. A bit of digging around later and there seems to be several studies indicating that black cohosh is not a general phytoestrogen, but may act like estrogen in only a few parts of the body: the brain (reducing hot flashes) and bone (potentially helping to prevent or treat osteoporosis), and, perhaps to some extent, in the vagina. It does not appear to act like estrogen in the breast or the uterus.

My takeaway at this stage is that black cohosh is probably perfectly safe, certainly not well understood and cannot with any confidence be said to be a topical antiager. Fortunately, KaplanMD's formulas do not rely on this herb, but on the synergistic effect of 10 active ingredients.