Propylene Glycol: Comedogenic Rating & Safety Profile
Also known as: 1,2-Propanediol · PG
A small humectant and solvent that helps actives penetrate the skin. Very common in serums and toners.
Quick facts about Propylene Glycol
Safe
0 = won't clog pores · 5 = highly pore-clogging
Low Risk
0 = inert · 5 = often irritating
Humectants
Generally considered safe
Typically yes
1,2-Propanediol, PG
Quick verdict
Propylene Glycol is a humectant with a safe comedogenic profile (0/5) and low risk irritancy (2/5). A small humectant and solvent that helps actives penetrate the skin. Very common in serums and toners.
What is Propylene Glycol?
Propylene glycol (PG, or 1,2-propanediol) is a small, water-soluble humectant and solvent. It helps actives penetrate the skin and gives toners and serums their fluid texture. Cosmetic-grade PG is purified to USP standards and is also widely used in pharmaceuticals and food (it is approved as a food additive in most countries). Despite occasional internet panic, PG has an extensive safety record at cosmetic concentrations.
Comedogenic Rating: What 0/5 Means for Your Skin
Propylene glycol is rated 0/5 comedogenic. It is too small and too water-soluble to clog pores.
Benefits for skin
- Boosts penetration of other actives
- Lightweight humectant
- Stable across pH ranges
Potential side effects & who should avoid it
PG has a 2/5 irritancy rating. About 2–4% of people develop a contact allergy with regular use, particularly those with sensitive or eczema-prone skin. If you have a documented PG allergy, look for products that use butylene glycol or pentylene glycol instead.
Best for
- All skin types
- Normal
- Combination
Avoid if
- Documented PG-allergic users
- Severely sensitive skin
How to use Propylene Glycol safely
If you have sensitive skin, patch test new PG-containing products on the inner forearm for 48 hours before regular use. Otherwise, no special precautions.
Commonly found in
Propylene glycol appears in toners, essences, serums, gels and many K-beauty products.
Found Propylene Glycol in your skincare?
Paste the full ingredient list into our INCI Analyser to see how this ingredient interacts with everything else in the formula.
Frequently asked questions
Other humectants to know
Hyaluronic Acid
A powerhouse humectant that draws moisture from the air into the skin, holding up to 1,000 times its weight in water.
Panthenol
Converts to Vitamin B5 in the skin. A humectant, soothing agent and barrier-repair active in one molecule.
Allantoin
A gentle keratolytic and soothing agent that calms irritation and softens roughness without exfoliating aggressively.
Sodium Hyaluronate
The salt form of hyaluronic acid. Smaller, more stable and faster to penetrate the upper layers of the skin.
Want the full picture on pore-clogging ingredients? Read our complete guide to comedogenic ingredients for the dermatology research behind the 0–5 scale and the full list of high-risk ingredients to avoid.
Written by ScanSkinAI Team · Last updated May 2026
This information is for educational purposes only. Always patch-test new products and consult a dermatologist if you have specific skin concerns.