The Mayo Clinic, a health care information provider, has stated in the latest addition of its Women's HealthSource newsletter, that ,while the active ingredients contained in such products can affect biological processes, they are not always subject to the same rigorous testing processes as pharmaceutical and medical products. Cosmeceuticals is a relatively new and fast-growing segment, but for many consumers, as well as regulation authorities, it often presents a problem as to how to define and categorize the many skin care product offerings that now clamor for retail shelf space. Anti-wrinkle creams, lotions and treatments largely bought over the counter in North America are the main focus of this segment, feeding on the current obsession with maintaining a youthful and healthy looking skin. Because these products use powerful and complex ingredients, they do not come cheap, which is probably why they have mainly won favor with the graying baby boom generation, whose unprecedented spending power is being channeled into buying such products. A recent survey by Kline and Company valued what it terms the global 'nutricosmetics' industry, which also takes into account beauty-orientated supplements, at $1bn - phenomenal growth for a category that was virtually non-existent five years ago. But with that rapid growth, consumer lobby groups and industry experts alike have all raised eyebrows over the classification of cosmeceutical products, both in the US and worldwide. In particular, the article in the Mayo Clinic newsletter draws attention to ingredients such as retinal, hydroxyl, coenzyme Q10 and peptides, which are all used to stimulate skin cell production, but in doing so affect the biological processes that regulate the skin's structure. In the US, such products are regulated by the Food and Drug Administration (FDA). Its official stand is that it does not recognize the term 'cosmeceutical', stating that the industry has devised the word to refer to cosmetic products that have medicinal or drug-like properties. Further to this, the FDA states that only if a product contains a drug properties will it review and approve the product, otherwise it does not officially approve cosmetics products. This stand has been criticized by industry experts as being, at the very least, ambiguous, leaving many cosmeceutical manufacturers in a kind of regulation twilight zone. Those individuals clued into this issue, such as the experts at the Mayo Clinic, believe that this kind of problem will continue to prevail until there is more defined regulatory guidelines for the segment.