PEG-8 Dimethicone

PEG-8 Dimethicone is a mid-weight dimethicone that has been modified to be water soluble (that’s what the “PEG-8” part indicates). This allows us to add the slippy, silky, de-tackifying, emollient benefits of dimethicone to watery formulations without the need for a separate emulsifying or solubilizing ingredient.

There are many different products from different manufacturers with the INCI of PEG-8 Dimethicone; my experience is with the product sold by Making Cosmetics. If yours is from a different source make sure you are researching precisely what you have as different PEG-8 Dimethicone products can have quite different properties.

PEG-8 Dimethicone

Clear yellow-tinted liquid

1–5%

Smooth, silky

Faint

Liquid at room temperature

3.4–3.7 (10% in distilled water)

Non-ionic

PEG-8 Dimethicone is water soluble.

PEG-8 Dimethicone makes it very easy to add the benefits of silicone (reducing tackiness, improving skin feel, adding a bit of richness, boosting slip, giving an expensive feel & finish) to watery products like serums, gels, cleansers, and sprays without requiring an additional emulsifying or solubilizing ingredient to incorporate it.

No, but it is a very useful ingredient to have if you love making hydrous (watery) skincare serums and are sensitive to tackiness/stickiness. It’s also an easy way to add emollience and slip to watery hair products.

PEG-8 Dimethicone only exists as a refined ingredient.

It’s a very easy way to reduce tackiness and add emollience and a silky, soft skin-feel to hydrous formulations.

It’s not natural and is not widely available.

The easiest option would be a different PEG’d silicone; My Skin Recipes sells quite a few. Read the descriptions for what you’re considering purchasing to ensure it meets your needs.

Consider what the PEG-8 Dimethicone is bringing to the formulation and keep this in mind as you consider alternatives. If it’s a leave-on skin formulation it is likely being included to improve skin feel and reduce tack. If it’s in a hair product it’s likely there for re-fatting/emollient reasons, add shine, and to smooth & detangle.

You could look at different water-soluble emollients/ingredients that are said to help reduce stickiness (e.g. PPG-20 Methyl Glucose Ether) or improve skin feel (e.g. Cromollient SCE [Di-PPG-2 Myreth-10 Adipate]). Read ingredient lists for water-based serums (especially expensive ones) to see what they use, and see if you can get it.

If you have a non-PEG silicone (like Dimethicone 350, cyclomethicone, or another cyclo-siloxane) or a natural silicone alternative that can work, but it won’t mix into the product like PEG-8 Dimethicone does. If the formulation is water-thin you could use it anyways and treat the product as a bi-phase formulation that needs to be shaken well before each use (it will separate when left). Or, you could try incorporating an additional ingredient to incorporate it, like Polysorbate 80 or PEG-40 Hydrogenated Castor Oil. You will likely need at least equal parts of solubilizer to silicone to get everything to mix together, and this can start to take up quite a lot of room in your formulation.

If the product will still work with a bit of a viscosity boost, you could use Polyacrylate crosspolymer-6 (Sepimax ZEN) (or a different gelling ingredient that has pseudo emulsifying abilities) to incorporate a regular silicone or natural silicone alternative. 0.4% Polyacrylate crosspolymer-6 (Sepimax ZEN) will make a product that is still fluid, and you should be able to incorporate 1–4% silicone. This will make for a hazy/creamy final product (the more silicone, the creamier it will appear).

If you are not very sensitive to tackiness in your formulations, you may be able leave it out and replace it with more water. This will be a noticeable loss, but is unlikely to be a make-or-break. If the PEG-8 Dimethicone is being used to solubilize in something like an essential oil you’ll need to eliminate that, too.

If re-fatting/emollience is the priority, other water-soluble re-fatting ingredients like Lamesoft® PO 65, PEG-40 Hydrogenated Castor Oil, or Olivem 300 may work.

Include it in the water phase of your formulation; if the formulation is hot processed, add it once the formulation has cooled below 50°C (122°F).

Stored somewhere cool, dark, and dry, PEG-8 Dimethicone should last at least 3 years from the production date.

PEG-8 Dimethicone will lather/foam a bit when mixed with water—it is a surfactant, after all!

30–100mL (1–3 fl oz)

 Buy it from an online DIY ingredient supplier; mine is from Making Cosmetics.