The active ingredient in self-tanners (or “sunless tanners,” as they’re also called) is dihydroxyacetone (DHA). DHA is a colorless sugar that interacts with the amino acid arginine in the dead cells of the stratum corneum, the outermost layer of your epidermis, which is the outer layer of your skin. The interaction of the DHA with these cells in the epidermis causes a color change, a browning of the skin.

Now, each and every day millions of dead skin cells are being sloughed away. (in fact, every month or so , you have a completely new epidermis. A whole new superficial you!) So as your old epidermis wears off, so does your sunless tan. That’s why self-tanners have to be reapplied every few days to maintain the maximum effect.

So for all you George Hamilton wannabes, if you covet that rich year-round tan, here are your choices: You can move to Florida or Southern California and slather yourself with baby oil and sit out on your patio all day with one of those aluminum reflectors-although you’ll be seriously courting melanoma ( and at the very least probably end up looking like all my grandmother’s leathery friends who used to sit outside their swim-club cabanas in the sun, the reptilian flab dangling from their upper arms as they shuffled their mah-jongg tiles). Or you can routinely rotisserie yourself in a tanning booth, which also poses some potential UV overexposure risk. Or you can take a tanning pill, most of which contain something called canthaxanthin, which is NOT approved by the FDA for use as a tanning agent, and which will not only turn your skin a nice Oompa-Loompa orange, but will also tint your tears, sweat, pee, and poop, AND which has been linked to hepatitis and something called canthaxanthin retinopathy (a condition in which yellow deposits form in the retina of your eye).

So you might just want to coat your bad self with that self-tanner… Just remember to rebaste every few weeks after molting.