Evaluating the Effectiveness of Cosmeceuticals

Evaluating the Effectiveness of Cosmeceuticals

I saw this interesting review study about cosmeceuticals. The article goes through and looks at the best scientific evidence available for various cosmeceuticals including…

1. Retinoids
2. Kinetin
3. Niacinamide
4. Soy phospholipids
5. Green tea polyphenols

Their conclusion, all 5 of these cosmeceuticals fall short of the proof standards for efficacy as proposed by Albert Kligman (<-famous skin researcher). Of the 5 examined, only Niacinamide was closest to meeting the Kligman standards.  But that’s not what I wanted to discuss.  More important is how cosmeceuticals should be vetted for figuring out whether they are worth including in your formulations or not.

Kligman standards

Albert Kligman was one of the most famous skin researchers in the United States. He was also the guy who coined the term ‘cosmeceuticals’.

He also posed three questions that you should ask about any cosmeceutical product that claims a beneficial physiological effect.

Skin penetration

1. Can the active ingredient penetrate the stratum corneum (SC) and be delivered in a high enough concentration to have an effect on the target in skin?

If enough of the ingredient can’t penetrate the skin then it is not going to have an effect. This is where most cosmeceutical ingredients fail.

Theoretical effect

2. Does the active ingredient have a known specific biochemical mechansim of action in human skin cells?

It’s not enough to penetrate the skin. There has to be some specific known target that the cosmeceutical is going to affect. If not, the ingredient probably won’t have a noticeable effect. Things like fruit stem cells or natural extracts fail in this area.

Clinical proof

3. Are there peer reviewed, double-blind, placebo-controlled, statistically siginficant clincial trials to substantiate efficacy claims?

And here is where almost all cosmeceutical ingredients fail. Practically no one publishes or even conducts studies of this nature and magnitude. It is probably too expensive or too risky (in case the ingredient doesn’t work) to do so.

Cosmetic chemists and cosmeceuticals

As a cosmetic chemist, you need to remain skeptical of efficacy claims of ingredients and require your suppliers to have answers to each of these three questions. They probably won’t have the answers you seek but if you start asking, they may start conducting the studies.