Bromelain
INCI · Bromelain · also Pineapple enzyme, Ananas Sativus Fruit Extract
How it works
Bromelain is not one enzyme but a mixture of cysteine proteases obtained from pineapple stem and fruit. Its cosmetic job is to cut protein, and the protein it is aimed at is the corneodesmosome — the rivet holding one dead surface cell to the next. Loosen those and the cells release on their own, which is exfoliation without abrasion and without the low pH a hydroxy acid needs.
That last point is the whole pitch. Proteases work near skin's own pH, so an enzyme exfoliant does not sting the way an acid at pH 3 can. The trade-off is stability: proteases lose activity in water over time, which is why these products so often arrive as a powder to be mixed in the hand, or as a short-contact mask that is rinsed off.
The evidence
Bromelain's protease chemistry is thoroughly characterised in the laboratory. Its cosmetic performance is not. There is very little published work comparing an enzyme exfoliant with a hydroxy acid on real skin, and almost nothing establishing how much activity survives a finished formula's pH, storage and shelf life. Enzyme activity is measured in units, not percentages, and cosmetic labels disclose neither.
It is worth separating this from bromelain's other reputation. A concentrated, purified bromelain-based preparation is a regulated medical product used in hospitals to debride burn wounds. That is a different concentration, a different purity and a different setting, and it says nothing at all about a rinse-off mask.
Suitability
- Dullness and rough texture, particularly where acids have not been tolerated
- Occasional use — this is a step, not a routine, and more often is not better
- Not on broken, sunburnt or actively irritated skin
- Anyone with a known pineapple allergy should skip it outright
Concentration
No established effective percentage exists, and any number quoted on a label is close to meaningless on its own. What determines whether an enzyme product does anything is activity — expressed in units such as GDU — together with the formula's pH and how long the product has sat on a shelf. Almost no cosmetic discloses any of that. In practice, contact time is the variable a user actually controls.
Conflicts & combinations
No documented chemical conflict with common actives, but two practical cautions. Stacking it with acids or a retinoid in the same session is the usual route to irritation, and the enzyme's mildness makes that easy to underestimate. And since a protease cuts peptide bonds indiscriminately, applying it in the same layer as a peptide serum is, in principle, working against yourself — apply actives after rinsing rather than underneath.
- Irritation
- Effective from
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Is bromelain gentler than glycolic acid?
It works at skin's own pH, so it usually feels gentler. Feeling gentler is not the same as being weaker or stronger in effect, and because the sting that would normally warn you is absent, it is easy to overdo.
How long should I leave an enzyme mask on?
Follow the product's own timing, which is usually a few minutes. Contact time is the main variable you control, and leaving it on far longer is the most common way to turn a mild step into an irritating one.
Does it help with acne?
There is no good evidence that it does. It loosens dead surface cells, which is not the mechanism behind inflammatory breakouts, and persistent acne is better addressed with ingredients that have been studied for it.
Can I use it if I am allergic to pineapple?
No. Bromelain is the pineapple protein itself, and allergic reactions to it are documented, including in people exposed to it occupationally. Patch testing any new enzyme product is sensible even without a known allergy.
Does the percentage on the label tell me anything?
Very little. Enzymes are judged by activity units rather than by weight, and a high percentage of an enzyme that has lost its activity in the jar does nothing at all.