Snail slime is the current It Girl in skincare. It’s been used since ancient times, and was revived in South American about 20 years ago as creme or gel de caracol, with brands such as Elicina. It really took off a few years when East Asian beauty companies caught wind of it and started jamming it into everything, from eye cream to BB cream. Today I’m going to go through some of the science behind snail slime.
What is snail slime?
The snail slime used in beauty products comes from the species Cryptomphalus aspersa (which used to be known as Helix aspersa Müller), which is the humble garden snail. The slime is usually listed in ingredients lists as snail secretion filtrate.
Snails actually release several types of slime, and it’s actually the slime that’s produced when the snail is stressed that’s in the products, not the stuff that they use to lube up the ground. The slime is commercially harvested by stressing cultivated snails, such as by poking them with a stick, or by feeding them salty water. The slime is purified by filtration (hence “secretion filtrate”). The snails aren’t killed in the process since they release unwanted chemicals when they die, but it doesn’t sound particularly pleasant either!
What’s in snail slime?
Snail slime contains a complex mixture of chemicals which normally help regenerate snail cells after they’ve been injured.
The mix includes:
- Glycosaminoglycans and proteoglycans – sugar-based molecules which can act as humectant moisturisers
- Allatoin – a soothing moisturiser
- Collagen and elastin – proteins which are too big to actually get through the skin, but might have a humectant effect
- Glycolic acid – chemical exfoliant and humectant
- Hyaluronic acid – humectant moisturiser
- Antimicrobial peptides – kill microbes
- Glycoprotein enzymes, copper peptides, zinc, iron, copper and manganese – not sure if these will do much. Some copper peptides (like GHK-Cu) can do some cool things, but “copper peptides” is a super broad description.
What does it do?
From the components in snail slime, it’s pretty clear that it’s going to be a pretty hardcore humectant moisturiser. But it could potentially do more!
A few in vitro studies have found some ways that snail slime might work on skin. Firstly, it can act as an antioxidant by scavenging free radicals and increasing the activity of superoxide dismutase (SOD), an enzyme which disables some free radicals. It also improves the structural support holding the skin up, by increasing the production and resilience of fibroblasts, and promotes assembly of the extracellular matrix. It also reduces the amount of matrix metalloproteinase, which normally breaks down collagen.
This sounds exciting, but does it translate when we use it on actual skin?
There have been a few clinical trials on snail slime, which doesn’t sound like much, but in the world of cosmetics ingredients this is pretty impressive! However, they use small sample sizes and only one is double-blind, controlled and randomised, which means their results should be taken with a grain of salt.
The most exciting results are from conditions that you wouldn’t normally treat with over-the-counter beauty creams – radiation burns and regular burns. Snail slime made the wounds heal faster. However, a Korean study on atopic dermatitis (eczema) didn’t find that snail slime did anything spectacular.
Then we get to normal skin (albeit slightly damaged from the sun) – it improved hydration and smoothness and reduced wrinkle depth, and while it’s tempting to say that it’s improving the structure of the skin, it’s more likely that it’s mostly the added hydration.
The scientific evidence that snail slime can actually help regenerate skin, particularly with unbroken skin, is pretty scarce. But it’s likely to be an absolutely fantastic moisturiser!
In vitro cell and molecular study on snail secretion mechanism: A. Brieva, N. Philips, R. Tejedor, A. Guerrero, J.P. Pivel, J.L. Alonso-Lebrero and S. Gonzalez. Molecular Basis for the Regenerative Properties of a Secretion of the Mollusk Cryptomphalus aspersa. Skin Pharmacology and Physiology 2008, 21, 15–22. doi: 10.1159/000109084
Clinical trial on 27 adults with deep partial thickness facial burns: D. Tsoutsos, D. Kakagia and K. Tamparopoulos. The efficacy of Helix aspersa Müller extract in the healing of partial thickness burns: A novel treatment for open burn management protocols. Journal of Dermatological Treatment 2009, 20, 219-222. doi: 10.1080/09546630802582037
Randomised controlled trial using 8% and 40% serum daily on 25 subjects with moderate to severely photodamaged facial skin: S.G. Fabi, J. L. Cohen, J.D. Peterson, M.G. Kiripolsky and M.P. Goldman. The effects of filtrate of the secretion of the Cryptomphalus aspersa on photoaged skin. Journal of Drugs in Dermatology 2013, 12, 453-457. (link)
Trial on 15 subjects with photoaging (no placebo not blinded): M J Tribó-Boixareu, C Parrado-Romero, B Rais, E Reyes, M A Vitale-Villarejo and S González. Clinical and histological efficacy of a secretion of the mollusk Cryptomphalus aspersa in the treatment of cutaneous photoaging. Cosmetic Dermatology 2009, 22, 247-252. (link)
Double-blind randomized controlled study on 20 subjects with atopic dermatitis: M-J Oh, S-M Park and H-T Kim. The Effects of Snail Secretion Filtrate on the damaged skin barrier’s recovery of the Atopic dermatitis. The Journal of Korean Oriental Medical Ophthalmology and Otolaryngology and Dermatology 2010, 23, 138-153. (link)
In vitro skin cell migration assay: M. C. Iglesias-de la Cruz, F. Sanz-Rodríguez, A. Zamarrón, E. Reyes, E. Carrasco, S. González and A. Juarranz. A secretion of the mollusc Cryptomphalus aspersa promotes proliferation, migration and survival of keratinocytes and dermal fibroblasts in vitro. International Journal of Cosmetic Science 2012, 34, 183–189. doi: 10.1111/j.1468-2494.2011.00699.x (full text)
In vitro study of the regenerative abilities of snail egg extract: J. Espada, M. Matabuena, N. Salazar, S. Lucena, O. Kourani, E. Carrasco, M. Calvo, C. Rodríguez, E. Reyes, S. González and A. Juarranz. Cryptomphalus aspersa mollusc eggs extract promotes migration and prevents cutaneous ageing in keratinocytes and dermal fibroblasts in vitro. International Journal of Cosmetic Science 2015, 37, 41–55. doi: 10.1111/ics.12167