How much N-acetyl glucosamine do you need? 2%+
The effective N-acetyl glucosamine percentage, by the vehicle-controlled trials, starts at 2%; no published dose comparison sets a ceiling.
Give it four to eight weeks, and possibly less: that is simply when it was measured.
how it was measured
Measured on Facial hyperpigmented spot area / appearance of hyperpigmentation, image analysis; measured at the trial's end, so possibly sooner.PMID 17348991PMID 19845667
What N-acetyl glucosamine percentage is effective?
One vehicle-controlled reading, by the maker: 2% N-acetyl glucosamine against the same moisturiser without it, double-blind and split-face for 8 weeks, reduced the appearance of facial hyperpigmentation, and 2% with 4% niacinamide did more (Bissett 2007, Procter and Gamble, headcount not in the abstract).
2%+
The trials, and what they used
- The combination was then confirmed in 202 women over 8 weeks against vehicle (Kimball 2010), which credits the pair, not the sugar.
- No dose comparison found; 2% is the only concentration tested and the only one on the market, so the floor is the product.
Is more than 2% N-acetyl glucosamine better?
Nobody has measured it: no published dose comparison sets a ceiling for N-acetyl glucosamine, so a percentage above 2% is above the trials' floor, not above a measured maximum. Only one strength has ever been tested, 2% (Bissett 2007), and it was tolerated.
Both of these agents are well tolerated by the skin.
The highest dose tested, in the paper’s words
- Both of these agents are well tolerated by the skin.
No published dose comparison sets a ceiling for n-acetyl glucosamine. A declared percentage above 2% is above the trials' floor, not above a measured maximum: the trials say from 2% it works, and say nothing about whether more does more.
What does the N-acetyl glucosamine percentage on a label tell you?
A name that states a percentage ("N-Acetyl Glucosamine 2%") is the only amount a cosmetic label ever declares, so it is the one number that can be read against the trials: at or above the 2% floor, or below it.
A name without a percentage leaves the position. The rules make a brand list ingredients in descending order of amount down to 1%, and in any order below it, so n-acetyl glucosamine above the 1% line is at least 1% and n-acetyl glucosamine below it can be any trace the brand likes. The floor the trials worked from is 2%, and a position alone cannot tell you whether a label reaches it.
The N-acetyl glucosamine percentages in our catalogue
One label carries it without a number, so the position is all there is:
- La Roche-Posay Hyalu B5 Suractivated SerumN-Acetyl Glucosamine sits 26th of 32, above the 1% line; the label does not say how much, and the trials worked from 2%.
Read on
- N-Acetyl Glucosamine: the glossary page what it does, who it suits, where it fits
- N-Acetyl Glucosamine vs Niacinamide
- N-Acetyl Glucosamine vs Vitamin C (LAA)
- N-Acetyl Glucosamine vs Retinal
- N-Acetyl Glucosamine vs Hydroxypinacolone Retinoate
- N-Acetyl Glucosamine vs Retinyl Retinoate
- N-Acetyl Glucosamine vs Azelaic Acid
Other actives with a dose the trials pinned:
- Niacinamide 2%+
- Vitamin C (LAA) 5%+
- Retinol 0.075 to 0.3%
- Salicylic acid (BHA) 0.5%+
- Lactic acid 8%+
- Glycolic acid 5%+
- Retinal 0.05 to 0.1%
- Retinyl Retinoate 0.06%+
- Tretinoin 0.025%+
- Adapalene 0.1%+
- Tazarotene 0.045%+
- Azelaic Acid 15%+
- THD Ascorbate 1%+
- Sodium Ascorbyl Phosphate 5%+
- Palmitoyl Pentapeptide-4 0.0003%+
- Caffeine 2%+
- Benzoyl Peroxide 2.5 to 5%
- Tea Tree Oil 5%+
- Hydroquinone 4%+
- Bifida Ferment Lysate 10%+
- Thiamidol 0.2%+
- Cysteamine 5%+
- Menthol 0.1 to 5%
- Peppermint Oil 0.5%+
- Alpha Lipoic Acid 5%+
- Ammonium lactate 12%+
- Acetylated Hyaluronic Acid 0.1%+
- 4-n-Butylresorcinol 0.1%+
- 4-t-Butylcyclohexanol 0.4%+
- Sphingomonas Ferment Extract 2%+