Rodan + Fields / Blog / Science of Skincare

The Science Behind Rodan + Fields Haircare Products

Rendering of haircare ingredient molecule

What is hair made of? Is it dead or alive, or both?

The hair on your head is made up two components, one that’s alive and one that is dead.  The living part under the skin, is called the follicle and the non-living part, made up of keratin, forms the visible shaft or strand.  Under a microscope the hair shaft looks to be covered in roof shingles or fish scales.  These are dead cells made up primarily of a hard protein called keratin, and are called cuticles.  Just like shingles or scales, healthy cuticles lie flat and protect the inner structure of the hair shaft from damage.  Damaged cuticles, either through exposure to harsh chemicals, environmental factors or otherwise, can expose the inner structure of the hair shaft, weakening the hair and leading to increased breakage.  Likewise, damaged or lifted cuticles make the surface of the hair rougher, making the hair appear dull, increasing the friction between individuals strands, compounding tangling and reducing manageability.

Forming a very thin layer on the cuticle is a coating of a natural lipid (or oil, called 18-MEA) which further protects the hair from environmental damage and provides shine, waterproofing (hydrophobicity) and reduces the friction between individual shafts.  If this natural oil coating is stripped off, either by over-washing or harsh treatments, the hair can become dull, weaker and more difficult to manage.

How does hair grow, and why is the scalp so important for hair?

The living part of hair, the root or follicle, is embedded in the scalp, where specialized cells are continually dividing, drawing energy and nutrients from the scalp and pushing out the growing hair shaft.  Hair growth, which for normal individuals is about ½ inch or 1-2 ounces per month, is the one of the most energy intensive processes in the body.[1]

Hair also grows in phases, with the growth phase lasting up to six years after which the strand briefly pauses before detaching from the scalp and falling out to be replaced by a new hair from underneath.  Roughly 1% of your hair is in this shedding phase, meaning for an individual with a normal head of hair (approximately 100,000 stands) the average amount of shedding is around 50-100 hairs / day.[2]

So, what can we learn from skincare?

There’s undoubtedly a trend in haircare to look to skincare for inspiration and new technologies which can support optimal health for the scalp and hair[3].  This is called the skinification of hair, but is there anything to it? 

The answer is, yes and no.  The skin on your scalp is similar to the skin on your face but with some key differences:

  • Your scalp skin has a lower functioning “barrier function” meaning that the scalp is more prone to water loss and greater inflammation.  Inflammation can easily lead to scalp irritation and trigger potential hair loss.
  • Your scalp is more highly vascularized in order to provide the follicle with all the nutrients and energy they need to continually make new hairs.
  • Your scalp has a unique microenvironment different than your face.

Overall, this means some of the key principles of skincare can be applied, but adapted to reflect these physiological differences.  Hydration of the scalp is important as are addressing any effects of environmental aggressors such as pollution, UV and other aggressors, which may accelerate the natural aging processes.

Cross-over skincare ingredients for haircare include:

Hyaluronic acid for hair

Hyaluronic acid (HA) is a great way to bring moisture to both hair and scalp, increase volume and reduce frizz.  HA is a natural component of the skin, including scalp skin, and helps retain water and improve physical resilience.  HA can be good for hair strands too, increasing volume, reducing frizz and improving shine.  HA comes in different sizes or “molecular weights”, for the best results, be sure to look for optimized ratios of both high and low molecular weights.

Amino acids for hair

Amino acids are important because they are the building blocks of hair and can therefore strengthen the structure of hair and potentially repair surface damage, improving hair luster and shine and even providing some color-fade protection.  Amino acids also make up part of the scalp skin’s natural moisturizing factors, which help the scalp skin remain hydrated and reduce the potential for irritation.  

Bio Ceramides for hair

In skincare ceramides are synonymous with hydration and in haircare it’s no different. R+F uses bio ceramides to smooth the hair and improve flexibility.  Improving the surface hydrophobicity of the hair strand can increase volume and shine.

Tri-energy Complex for hair

R+F TriEnergy Complex is an exclusive, patent-pending technology that blends Sandalwood, Indian Kino Extract and Omega 6 Fatty Acid into a unique ratio for maximum potency. The Ayurvedic inspired complex has been shown to improve the strength of the skin barrier, meaning it helps the scalp retain more water.  The TriEnergy complex also energizes surface skin cells, and we already know energy is super important for healthy hair.

Acetyl Glutamine (AG) for hair

Acetyl glutamine is a form of glutamine modified to make it easier to formulate into topical products.  Glutamine is a multipurpose amino acid found throughout the body. Although not commonly used in skincare or haircare, research by Rodan and Fields has shown the molecule to be beneficial in a number of ways including energy production.

Why two haircare regimens?

Just like our skincare products, R+F haircare products are developed, not for specific hair types, but around concerns; volume and smoothing.  The Volume+ Regimen is directed towards creating fuller, thicker, more voluminous-looking hair, with less fall out due to breakage.  The Smooth+ Regimen is designed to hydrate and repair, reduce frizz and increase shine.  Either regimen is suitable for all hair types.

Article by Simon Craw, PhD

Dr. Simon Craw holds a PhD in Chemistry from University of Manchester and held academic posts at the University of Rio de Janeiro (Brazil) and University of Sydney (Australia). He has over 25 years’ industry experience in pharmaceutical, biotechnology and skin care research and development.  He began his career at Merck Research Laboratories before moving to a series of start-ups and early-stage biotechnology and skincare companies. At Lifeline Skincare, Dr. Craw helped develop and commercialize one of the first and most innovative stem cell extracts used in topical cosmetics.  At Rodan + Fields Dr. Craw has brought a number of skincare innovations to market including Retinal MD, one of the most powerful non-prescription retinoids and Total RF Serum a breakthrough anti-aging serum powered by a patent-pending new technology targeting cellular energy, RF TriEnergy Complex.


[1] Lemasters JJ, Ramshesh VK, Lovelace GL, Lim J, Wright GD, Harland D, Dawson TL Jr. Compartmentation of Mitochondrial and Oxidative Metabolism in Growing Hair Follicles: A Ring of Fire. J Invest Dermatol. 2017 Jul;137(7):1434-1444. doi: 10.1016/j.jid.2017.02.983. Epub 2017 Mar 23. PMID: 28344061; PMCID: PMC5545130..

[2] Draelos ZD.  Hair Care-an Illustrated Dermatologic Hand Book. 1st ed. United Kingdom: Taylor and Francis; 2005, Whiting DA. Male pattern hair loss: current understanding. Int J Dermatol. 1998 Aug;37(8):561-6. doi: 10.1046/j.1365-4362.1998.00542.x. PMID: 9731996.

[3] See for example

[4] Majewski G, Craw J, Falla T. Accelerated Barrier Repair in Human Skin Explants Induced with a Plant-Derived PPAR-α Activating Complex via Cooperative Interactions. Clin Cosmet Investig Dermatol. 2021 Sep 18;14:1271-1293. doi: 10.2147/CCID.S325967. PMID: 34566418; PMCID: PMC8458040.