Galderma Benzac 10% Gel

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.

One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).

Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.

You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.

Silver nanoparticle gel performed comparably to the antiobiotic clindamcyin in a double-blinded, randomized study for treating moderate acne (both were combined with benzoyl peroxide).

It should be noted the overall body of clinical evidence is still pretty thin, and some in-vitro studies have found that commercially available colloidal silver solutions didn't actually show antimicrobial activity against tested organisms.

The most well-known risk of using this ingredient is argyria. Argyria is the condition where silver builds up in the body's tissues and causes a permanent bluish-gray skin discoloration (and this is mostly associated with oral ingestion rather than topical use).

The FDA ruled in 1999 that over-the-counter colloidal silver products are not generally recognized as safe and effective and the NCCIH notes that silver has no known beneficial function in the body and is not an essential mineral.

It's a good idea to talk to a dermatologist first and stick to well-formulated topical products if you're considering a colloidal silver skincare product.

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!