Beauty from Within is a growing category among consumers who want to not only feel healthy, but also look healthy. In a 2022 survey conducted by The Benchmarking Company, 92% of respondents (US female beauty buyers) said they support an inside-out approach to beauty. This kind of support from consumers suggests how the Beauty from Within market has been able to achieve such growth over the past years: in 2022, the hair, skin, and nail supplement category reported 29% year-over-year growth (ClearCut Analytics and SPINS data).

Although the targeted benefits may seem cosmetic, the reasons why consumers are looking for these products are often rooted in an internal deficiency of nutrients. Issues like hair thinning, brittle nails, or dehydrated skin can affect all people, and are indications that a certain nutrient may be missing from a person’s diet. In this educational piece, we’re going to take a different approach to this topic: rather than looking at the studied benefits of an orally-ingested Beauty from Within ingredient (such as collagen or hyaluronic acid), we’re going to focus on the mechanisms of action – how and why these kinds of ingredients work.

With topical ingredients, like a lotion or a lip balm, the localized effects are easy to understand. But what pathways does an orally-consumed supplement, or an organic compound in food, take to get from our mouth to our skin, hair or nails to improve their health and appearance? Keep reading to find out!

The Integumentary System

The integumentary system is an organ system that consists of the skin, hair, nails, and exocrine glands. Let’s start with the skin – the largest organ in the body. Our skin contains collagen bundles and elastin in the dermis layer. Collagen and elastin (both of which are proteins that have done particularly well in the Beauty from Within market) work together, with collagen providing rigidity and elastin providing recoil, or stretchiness. Keratin is another protein that helps form the outer layers of the skin (the epidermis) and heal wounds. Ceramides are lipids that form the natural skin barrier, sealing in moisture and protecting the skin from environmental change. In the past few years, ceramides have gained traction in skin health products due to their ability to reduce the appearance of wrinkles and mitigate breakouts. Nails are accessory organs of the skin, made of sheets of hardened keratinocytes (note the root word “keratin” here). The integumentary system also includes the nerves and blood vessels throughout these organs. When people are looking to target skin, hair, and nails with dietary supplements, the integumentary system is the solution to achieving beauty and health benefits.

The Pathway to Hair, Skin, and Nail Health

Nutricosmetic ingredients are orally-consumed dietary ingredients for skin, hair, and nail health – they represent the Beauty from Within category. When nutricosmetic ingredients are ingested, they have to pass through the stomach and intestines, and must be ultimately distributed to all parts of the skin, hair follicles, and nails in order to be effective. So, how do they do this? The key is blood circulation. When nutricosmetic ingredients are digested by the stomach and passed to the gut, they are then able to cross into the bloodstream and can be carried throughout the body. Bioavailability is critical here: if the dietary ingredient is not sufficiently bioavailable, it will not effectively pass the from the gut to the blood, and its intended effect is diminished or completely canceled.

In addition to bioavailability, a significant aspect of the ingredient pathway is that nutricosmetic ingredients can broken down by the gut into their metabolite components – in the case of proteins, these would include amino acids and peptides. These metabolite components can easily be carried by the blood to locations where they provide the right nutritional support. For example, when the metabolite components are brought to the skin cells, they can be used to produce collagen, elastin, keratin, etc., and thereby support the integrity and elasticity of the skin.

Another example is hydrolyzed proteins – these are proteins that have been broken down into their subcomponents (like amino acids and peptides). These subcomponents are much more bioavailable and can be “reassembled” into their structural components by the cells in the skin. In this manner, hydrolyzed collagen, keratin, and elastin are more effective in providing beautifying and healing effects.

Butyrate: The Intermediary Pathway

Dietary ingredients can also act through different kinds of intermediaries to affect the revitalization, regeneration, and re-elastification of the skin, hair, and nails. Intermediaries are signaling molecules that can transport a “message” from the gut to the integumentary organs. The most intriguing example of this is butyrate, one of the key short chain fatty acids (SCFAs). Over 80% of the cells in the body have butyrate receptors, which can then upregulate or downregulate skin cells. When we hear that probiotics can affect skin health (through the gut-skin axis), this does not mean that the probiotics themselves are transported to the skin. Instead, the probiotics feed on prebiotics in the gut and then generate the postbiotic butyrate. Butyrate is transported by the blood to the hair, skin, and nails. Recent ingredient development has created a way in which butyrate can be directly generated in order to bypass the necessity for probiotics (learn more about ButyraGen™ here).

Closing Thoughts

By these mechanisms, Beauty from Within nutricosmetics work from the inside out. Nutricosmetics include proteins, peptides, minerals, vitamins, carotenes, omega-3s, and plant extracts. These dietary ingredients are consumed orally, digested in the gut, and transported by the blood to cells across the body. Once they arrive to these cells, they can effectively support the development and growth of the structural components of the skin, hair, and nails. It’s these structural components which provide the beauty effects that people are looking for – glowing, healthy skin, silky smooth hair, and non-brittle nails.


NutriScience Innovations develops and markets innovative ingredients for the dietary supplement and functional food markets. To learn more about NutriScience’s Beauty from Within ingredients – including KeraGLO® hydrolyzed keratin, ElastaGLO® hydrolyzed elastin, NutriGLO® glutathione, ButyraGen® direct butyrate generator, and more – please contact [email protected].