CLOCKWISE FROM TOP-LEFT: Hairdresser’s Invisible Oil ($38), Bumble and Bumble. The Salon and Day Spa at Amagansett Square, 6 Amagansett Sq., 267-6677. Elixir Kultime ($54), Kérastase. 27 Hampton Salon, 27 Hampton Road, Southampton, 377-3107. Bath Oil for Glowing Radiance ($60), Ila-Spa. Cleansing Bar ($10), Moroccanoil. Bluemercury, 8285 Jericho Tpk., Woodbury, 516-367-1300. Superbly Restorative Argan Dry Oil ($32), Kiehl’s. Roosevelt Field Mall, 630 Old Country Road, Garden City, 516-535-1380. Body Souffle ($52), Moroccanoil. Bluemercury, 8285 Jericho Tpk., Woodbury, 516-367-1300.

More than 3,000 miles away, in the craggy slopes linking Marrakesh to the coastal port of Essaouira is the epicenter of the decade’s defining beauty ingredient. It’s here, under the scorching Moroccan sun, that cooperatives of Berber women harvest the gnarled nuts of the argan tree, grinding them into a thick brown paste between rocks before it’s transformed into the final product: bottles of glossy argan oil destined for the hair and skin of consumers around the world.

“The reason it’s become such a sought-after ingredient is quite simply because it really works,” says spa owner Deborah Thompson, who has traveled between the Hamptons and Morocco for the last 12 years. She sees it as a natural fix-all for a host of beauty problems, including wrinkles, eczema, psoriasis, and skin inflammation. “Argan has a multitude of uses and acts fast,” she says, adding that she’ll be incorporating it into a host of new treatments this summer at her namesake spa in Montauk.

The spotlight on argan oil is all thanks to a benefits list that reads like a who’s who of antiaging—think vitamin E, beta-carotene, squalene, and ferulic acid (an antioxidant that has increased potency under UV rays)—that makes it the perfect summer go-to ingredient. “It has cell-regulating properties, which are very hot right now,” says dermatologist Dr. Neil Sadick, who spends most of his summers doing house calls in the Hamptons. “It also contains the highest dose of gamma tocopherol (vitamin E) and helps to keep the immune system strong.”

And now word is spreading: Moroccanoil (arguably the brand which kick-started the trend six years ago) has added five new luxe body products to its popular line. Argan oil is the linchpin ingredient of Kiehl’s Superbly Restorative Argan range. Bumble and Bumble’s big launch of the summer, Hairdresser’s Invisible Oil, contains argan oil. Even L’Oreal will join the trend this July with the introduction of EverSleek Precious Oil Treatment, designed to smooth troublesome hair for 48 hours.

The sheer demand for the oil has been a boon for the female-run groups who produce it (still using the same centuries old techniques, which take several days to produce just one liter of liquid). And now that their 10,000-square-mile argan-growing region has been designated a biosphere reserve by Unesco, the future is assured. Whether they can keep pace with our world’s rampant demand is another question. Perhaps one day Hamptonites will be getting their argan-fix (along with our Pinot Noir) from the bucolic North Fork….