Hyaluronic Acid: Comedogenic Rating & Safety Profile

What is Hyaluronic Acid?

Hyaluronic acid (HA) is a glycosaminoglycan — a long-chain sugar molecule — that occurs naturally throughout the human body, including in skin, joints and eyes. In cosmetics it is produced by bacterial fermentation, making it both vegan and identical to endogenous HA. Its defining trait is hygroscopy: a single HA molecule can bind up to 1,000 times its weight in water. That makes it the most powerful humectant in mainstream skincare and a go-to ingredient for restoring plumpness to dehydrated skin. Different molecular weights penetrate to different depths — high-MW HA sits on the surface and forms a hydrating film, while low-MW HA reaches deeper layers of the epidermis.

Comedogenic Rating: What 0/5 Means for Your Skin

HA is rated 0/5 comedogenic. It is a water-binding sugar molecule with no oils, waxes or fatty acids that could physically block a follicle. Every skin type — including the oiliest, most acne-prone skin — can use it daily without any pore-clogging risk. In dry climates, however, low-MW HA can occasionally pull moisture out of deeper skin layers if not sealed with an occlusive moisturiser, leaving skin feeling tighter rather than plumper.

• Plumps fine lines and surface dehydration within minutes
• Compatible with virtually every active ingredient
• Non-comedogenic and safe for the entire face including the eye area
• Helps reinforce the moisture barrier when layered under occlusives

HA is one of the safest ingredients in skincare. True allergic reactions are vanishingly rare. The most common 'side effect' is feeling tight or dehydrated in arid environments — this happens when HA pulls moisture from the air, but if there is no humidity to draw from, it pulls from your skin instead. The fix is simple: apply HA to damp skin and immediately seal with a moisturiser containing occlusives like dimethicone, squalane or petrolatum.

Apply HA serum to slightly damp skin morning and night, then immediately layer a moisturiser on top to lock the hydration in. Pairs safely with every other active ingredient. Multi-molecular-weight HA serums are ideal because they hydrate at multiple skin depths simultaneously.

Related forms: Sodium hyaluronate is the salt form, smaller and faster-penetrating; both behave the same for daily use.

Hyaluronic acid is in serums, moisturisers, sheet masks, eye creams, lip products, sunscreens and most modern cleansers. It is also widely used in injectable dermal fillers, but the topical and injectable forms behave very differently.