Silk is created by silkworms that eat organically grown mulberry leaves, a process that removes carbon dioxide from the air.
But while most silkworm cocoons are used for making fabric, Silk Therapeutics uses the protein from discarded silkworm cocoons to make liquid silk.
Because it doesn't need the same high-quality cocoons that would be used in fabric, the company can use cocoons that would otherwise be wasted.

To liquidize the silk, the company found a way to first discard the gluelike coating of the original silk fiber, which can cause an allergic reaction when it comes into contact with skin. This leaves the fibroin, the pure silk fiber. Since the fiber alone has a molecular size that helps it penetrate into the skin, it works better than hydrolyzed silk, which contains bigger molecules that don't penetrate as deeply in the skin. It has beneficial properties too.
"Collagen and silk are skin's good friends. Silk is a protein material, which is biocompatible and can help the skin become firmer and look firmer in a way that it binds the collagen within your skin," Rebecca Lacouture, CEO and Founder of Silk Therapeutic
According to the executive, the skincare line consists of just 12 ingredients, compared to regular products such as moisturisers, which often contain up to 40 or 50 ingredients.

For Lacouture, who was diagnosed with ovarian cancer at 27, it was important to develop simple, safe and non-toxic formulas. "For us, it was important that it performs, because we don't want anyone to ever have to compromise the performance of skincare. People shouldn't need to trade safety for effectiveness"

There's certainly a market for sustainable fibres. According to a 2017 study, the market for sustainable products was worth over $3 trillion, now that a third of consumers are choosing to buy from brands they believe are doing environmental good. The shift has seen the emergence of several sustainability-driven startups, including Bolt Threads, which makes spider silk from microbugs, and Modern Meadow, which produces lab-grown animal-free leather.