Anastasia Nu-Brow Brow Enhancing Serum sent me off on a chain of thought. First off (being from the UK) I conjured up a mental picture of Dennis Healey, a British politician remembered only for the mutant mega-caterpillar forms above his eyes. This led, inevitably, to wondering why anyone would want bushy brows. Then I thought about eyelash growth products, like Jan Marini and Revitalash and all the recent controversy around the safety of the active ingredient. This led, inevitably, to wondering if the key ingredient in Anastasia Nu-Brow is safe and/or effective.
The secret sauce in Nu-Brow is called Capigen. This is mostly a concoction of amino acids and emollients. Amongst them, however, are a couple of promising ingredients. Ultimately, I was disappointed: on closer investigation neither are entirely convincing. One is homotaurine, also called 3-aminopropane sulfonic acid. This is an analogue for GABA, the ingredient that is cropping up in face creams as a neurotransmitter (it is supposed to inhibit muscle movement). Hmm. After much rummaging, it appears that homotaurine is used in hair care products fairly frequently. I couldn't really find any evidence that it promotes hair growth, although there are some (unsubstantiated) claims that it slows hair loss.
The other potential brow booster is biotin. A vitamin B7, it is used in several hair loss treatments. However, there is no evidence that it works and topical application is likely to be effective since biotin can't be absorbed through the skin.