What is it? Lecithin is a blend of lipids that can be found in egg yolks, soybeans, and sunflower seeds. The precise composition varies with the source of the lecithin; I typically use soya lecithin. This entry does not distinguish between soya and sunflower lecithin—both are lecithin.
INCI Lecithin
Appearance It can be purchased in dry granules or in liquid form (the liquid is a dark amber colour). The liquid form contains up to 35% triglycerides, and is much easer to use.
Usage rate Typical use is 0.5–5%; the CIR limits its use to 15% or less in leave-on products.
Texture Waxy granules or a smooth, viscous, syruppy liquid.
Scent Somewhat nutty—different sources can vary in strength
Absorbency Speed Very slow.
Charge Non-ionic
Solubility Oil
Why do we use it in formulations? Lecithin can serve a variety of purposes in formulations.

It does have emulsifying properties, creating water-in-oil emulsions. I’ve found HLB values from 4–9 listed for lecithin, so check with your supplier for the one you have. The emulsifying properties are fairly limited, and emulsions made with lecithin as the lone emulsifier are quite tricky to create. If you are looking to create lightweight, fast-absorbing creams, lecithin is not going to be your emulsifier of choice.

Lecithin is an excellent emollient and occlusive, making it wonderful in products for extremely dry skin or lips (it also helps with barrier repair). Lecithin also contributes a beautiful creamy consistency to anhydrous lip products. Its consistency is really unique—gooey, silky smooth, and sticky in high concentrations—and it brings those properties to our products in varying amounts, depending on how much is used. Lecithin contains antioxidants, thickens our products, and functions as a humectant (this is very rare for oil-soluble ingredients).

While I have made emulsions with lecithin, I prefer to use it in anhydrous products to make them richer and creamier. I especially love it in lip products for the rich, creamy feel.

Do you need it? No, but if a recipe calls for lecithin it is very hard to substitute.
Refined or unrefined? Make sure you get the liquid version; the granules are a slightly different composition and are much harder to work with. If it’s a choice of granules or nothing, go with nothing.
Strengths Excellent multi-purpose emollient and occlusive that is wonderful for the skin.
Weaknesses Can be harder to find than some ingredients.
Alternatives & Substitutions Liquid lecithin from different sources can be used interchangeably (soy, sunflower).

I really can’t recommend anything as a great alternative to lecithin. You could try blending some lanolin with castor oil, but that will mostly just approximate the consistency and also be oil soluble.

Lecithin cannot be used as a replacement for emulsifying waxes like Polawax, Olivem 1000, Ritamulse SCG (Emulsimulse, ECOMulse), Glyceryl Stearate (and) PEG-100 Stearate, etc., or vice versa. It is also not a suitable alternative for solubilizers like Polysorbate 20Polysorbate 80, or PEG-40 Hydrogenated Castor Oil. This is partly because lecithin creates water-in-oil emulsions while all of these emulsifiers/solubilizers create oil-in-water emulsions, and partly because lecithin is quite finicky to work with and has formulation requirements that are quite different from what you’d encounter in formulations designed to use any of these ingredients.

How to Work with It Include lecithin in your heated oil phase.
Storage & Shelf Life Stored somewhere cool, dark, and dry, lecithin should last about two years.
Tips, Tricks, and Quirks Lecithin can help stabilize emulsions as a co-emulsifier.
Recommended starter amount 100–200g (3.3–6.6oz)
Where to Buy it  Buy it from an online DIY ingredient supplier or Amazon.

Some Formulations that Use Lecithin

Skills

Posted on

January 15, 2019