Caffeine

The same ingredient that wakes you up in the morning does something useful for skin and scalp too — but not quite everything the internet claims. Here’s what caffeine’s actual, published mechanisms are.

Description

What is it?

Caffeine is a naturally occurring alkaloid — the same compound found in coffee and tea — used in cosmetics for its ability to penetrate the skin barrier and act on cells directly underneath it.

What does it actually do?

According to a review of caffeine’s mechanisms in cosmetic use (Herman A, Herman AP. “Caffeine’s mechanisms of action and its cosmetic use.” Skin Pharmacology and Physiology, 2012) (DOI) , caffeine has several confirmed actions relevant to skin and scalp:

Antioxidant activity. Caffeine has meaningful antioxidant properties, helping protect skin cells from UV-related damage and slowing visible photoaging. (Widely accepted consensus.)
Supports microcirculation. Topical caffeine increases blood microcirculation in skin — part of the mechanism behind its use in under-eye and puffiness-focused products. (Widely accepted consensus.)
Affects fat breakdown locally (lipolysis). Caffeine inhibits an enzyme (phosphodiesterase) involved in fat storage in cells, stimulating local fat breakdown — the basis for its use in anti-cellulite and de-puffing formulas. (Widely accepted consensus.)
Inhibits 5-alpha-reductase. This is caffeine’s most relevant mechanism for hair — 5-alpha-reductase is the enzyme that converts testosterone into DHT, the hormone most linked to pattern hair thinning. Caffeine’s inhibition of this enzyme is the published basis for including it in hair-growth-focused formulas.

Who is it good for?

Under-eye use: anyone dealing with morning puffiness or looking for a lightweight, quick-absorbing under-eye formula. Scalp/hair use: anyone in a hair-thinning-prevention routine, as a supporting ingredient alongside the formula’s other actives — not a standalone treatment.

No real precautions — topical caffeine at cosmetic concentrations is well tolerated across skin types.

How Mystic Dust uses it

Formulated in Under Eye Gel (alongside Eyeseryl peptides and Niacinamide), and as Encapsulated Caffeine in Hair Growth Serum, alongside plain Caffeine in Hair Growth Shampoo and Scalp Reset Shampoo. Also formulated into the Scalp Strength Advanced Hair Growth Shampoo, alongside Redensyl, Anagain and Saw Palmetto.

Pairs well with

Peptides (Eyeseryl, Matrixyl) for under-eye use; Redensyl, Anagain and Niacinamide for scalp/hair use — all already formulated alongside caffeine in the relevant Mystic Dust products.

Use with caution alongside

Nothing specific at cosmetic concentrations.

Research & Findings

According to PubMed: - Herman A, Herman AP. “Caffeine’s mechanisms of action and its cosmetic use.” Skin Pharmacology and Physiology, 2012;26(1):8-14. DOI