I rode the subway the other day with a woman whose shoulder length brown hair could only be described as silky. It was as smooth as a mill pond with a glossy sheen that you could almost see your face in. I am way too English to accost total strangers and ask them what shampoo they use, so I fed my curiosity with a question: does silk in hair products - such as Biosilk Shampoo or John Masters Organics styling gel - make hair silky?

Silk is composed of two proteins, sericin and fibroin. Soluble, post-spun sericin(a) is shown to adhere to keratin of skin and hair, even after very short incubation period. This results in a perceptible homogeneous protective film. So does this mean that the smooth as silk results of hair treated with silk are merely the superficial results of this film?

Mostly yes, but silk has one feature that is helpful to hair. It can retain 10,000 times its weight in water, thus helping prevent hair from getting dry and brittle. Although I read somewhere that Biosilk claims that silk has the same number of amino acids as hair, I'm not sure that this is strictly true. Apparently, silk fibroin yields only one-tenth of the basic amino acids that would be found in wool (the primary source of keratin in your shampoo).

Biosilk (as with most other silkspun hair products) use hydrolized silk. Hydrolyzed proteins have been broken down into smaller sized molecules that are easier to put into shampoos and conditioners. However, they aren’t very effective because smaller molecules smaller are less effective at film forming. Apart from panthenol (vitamin B), there isn't anything in Biosilk Silk Therapy that is contributing to hair health. A better bet would be Nutra-Lift's Goat Milk shampoo with, as well as silk, host of organic botanicals such as pomegranate and tea.

Ingredients in Biosilk Silk Therapy Shampoo

Cyclomethicone, Dimethicone, SD Alcohol 40B, C12 15 Alkyl Benzoate, Ethyl Ester of Hydrolyzed Silk, Panthenol, Phenoxyethanol, Methylparaben, Propylparaben, Fragrance, Hexyl Cinnamic Aldehyde, Benzyl Benzoate, Linalool, Gamma Methyl Ionone, Citronellol, Lilial, Hydroxycitronellal, Geraniol, Eugenol.