Actress Michelle Williams was recently reported as saying that NIA24 Sun Damage Prevention Mineral Sunscreen SPF 30 ($45) is “the best I’ve ever tried.” Given what a dull product NIA24’s sunscreen is, I was surprised at the accolade and wondered if I could smell a rat. It turns out my nose was more reliable – and literal – than I realized.

NIA24 is best known for its use of niacin, a form of vitamin B, which it couples with myristyl nicotinate as the delivery system for slow release. Although the delivery system is in NIA24 Sun Damage Prevention Mineral Sunscreen SPF 30, the niacin doesn’t appear to be. When I started to look at what is here, I found that there is a lot of fragrance. But rather than coming up smelling of roses, there is a whiff of sex.

But before we get to the sex part (I know, I’m a tease), I should mention that there are a few mysterious ingredients here – and the one thing I don’t like about something I put on my face is not knowing what it is. And, as you’d expect, I feel some level of responsibility for Michelle Williams’ face as well.

I spent ages trying to track down a UV absorber called benzotriazolyl dodecyl p-cresol, about which very little information seems to exist. And there’s another NIA24 product that I can’t get to the bottom of: 1,5,5,9-Tetramethyl-13-Oxatricyclotridecane. The only thing I can tell you about it with any certainty is that it turns up in a lot of NIA24 products. My best guess is that it is a chemical fragrance and this isn’t the first time that a NIA24 product has had me chasing around for something that turned out to be a perfume (see my review of NIA24 Physical Cleansing Scrub).

Now the thing about about NIA24 is that fragrance seems to play a big role. There are several chemical fragrances here and whatever smell they impart are being boosted by maltol, a flavor enhancer that may increase aluminum absorption by the body. Which is not a welcome attribute since there is Aluminum Hydroxide here.

The most interesting thing about NIA24’s sunscreen is that it has nutmeg extract. Studies on male rats have demonstrated its aphrodisiac effects. More usefully (although that might depend on your take on aphrodisiacs), it is an antioxidant. And, I have just discovered, nutmeg is an anti-depressant.

Perhaps that’s why Michelle Williams feels so good about a sunscreen that is mostly a bunch of different silicones and mediocre emollients. Now on the subject of aphrodisiacs, I couldn’t help but notice that pentadecalactone is in NIA24’s sunscreen. This is one of the key phermones produced by the apocrine glands of the male armpit, and is credited with attracting females.

So that’s how a very non-descript sunscreen became a celebrity pick. Sex, as they say, sells.

Active Ingredients: Titanium Dioxide – 9.45%, Zinc Oxide – 3.6%.

Inactive Ingredients: Cyclomethicone, Water (Aqua, Eau), Octyldodecyl Neopentanoate, Myristyl Nicotinate, Zea Mays (Corn) Starch, Stearic Acid, Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone, Neopentyl Glycol Diheptanoate, PEG/PPG-18/18 Dimethicone, PEG-12 Dimethicone, Tocopheryl Acetate, Myristica Fragrans (Nutmeg) Kernel Extract, Caprylyl Glycol, Methicone, Benzotriazolyl Dodecyl p-Cresol, Cetyl Alcohol, PEG-10 Dimethicone, Bisabolol, Aluminum Hydroxide, Disodium EDTA, 1,5,5,9-Tetramethyl-13-Oxatricyclotridecane, Maltol, Pentadecalactone, Dimethiconol, Polysilicone-11, Methyldihydrojasmonate, Phenoxyethanol, Citronellol, Eugenol, Geraniol, Isoeugenol, Limonene, Linalool