Dear Valerie: I’m formulating a hair serum and would love to incorporate peptides. My formula is anhydrous. Do you have any recommendations? 

– Dry Aye

Dear Dry:

I’m often asked by raw material suppliers for a wish list of ingredients. The wish list hasn’t changed much over the years. With so many ingredients available to the formulating chemist, we pretty much have everything we could want. 

Two items remain on the list after all these years: 

1. A natural carbomer that’s 100% identical. (I’m sorry, raw material suppliers! Your natural gums and alginates do not cut it!) and 
2. Oil soluble actives, such as peptides.

A few oil soluble peptides have come to market, like Sederma’s Matrixyl 3000 OS or Argireline YOUth Peptide, but they come with quite the entourage of co-emulsifiers. It makes sense; peptides on their own are typically water soluble, so you need some way to get these little wonders to stay in oil. There are a couple other peptides purported to be oil soluble but I didn’t have any information on their full composition to report; typically, a peptide would need lipid moieties attached.

Seiwa Kasei offers hydrolyzed proteins from either silk or keratin as part of its Promois series, but these are not necessarily peptides and are animal derived. However, they’re readily oil soluble and have excellent clinical studies. As an aside, if you aren’t on Daichi Iwasaki’s email list for Seiwa Kasei, you should be. He has the best ingredient emails on planet Earth and they’re a joy to read.

You could consider taking any peptide of interest and using a polyglyceryl-based, water-in-oil emulsifier to see if you can solubilize a water-based peptide into your oil system. The reason I explicitly used the term polyglyceryl-based is that those generally don’t require heat and inherently create fluid systems… maybe it will work for you, who knows!

Valerie George
askvalerie@icloud.com

Valerie George is a cosmetic chemist, science communicator, educator, leader, and avid proponent of transparency in the beauty industry. She works on the latest research in hair color and hair care at her company, Simply Formulas, and is the co-host of The Beauty Brains podcast. You can find her on Instagram at @cosmetic_chemist or showcasing her favorite ingredients to small brands and home formulators at simply-ingredients.com