What Happens When You Use P50 On Your Scalp

Scalp treatments. Have I got your attention? If you're already scanning this webpage for something else to click, I get it-even though they're beauty's buzziest haircare treatment, I've let several pass through the ITG product closet without feeling the need to take one home for a spin. Because, who are scalp treatments even for? I never struggled with dandruff or scalp buildup from frequent product use, so I thought the answer to that was: "Not me." Much like my laissez-faire relationship with the rest of my hair, I hadn't been paying too much attention to my scalp because I was pretty sure I didn't need to. Who cares that it was oily? It was fine! Except for the fact that usually my hair was too greasy to wear down a day after washing. But that was normal for straight, medium-fine textured hair, right?

"Your scalp is of the same structure as the skin on your face, so if your face is dry or oily, your scalp will likely be the same," hairstylist Frederic Moine told me when I sat in his chair at the Paul Labrecque Salon and Spa in Manhattan's Core Club last week. I was there to get what was basically a two-hour-long Biologique Recherche facial for my scalp, complete with the brand's cult-favorite pH-balancing acid treatment, P50. Frederic noted that Paul Labrecque is one of only two salons in the US to use Biologique's hair care line, and has become a destination for those already devoted to the brand's skincare products. He explained that while most scalp treatments are marketed for regulating dandruff, P50 is great for dry and oily scalps alike. "An oily scalp and dry scalp both indicate the same thing," he revealed with a charmingly French shrug. "In both instances your scalp is overreacting." Just like how P50 balances my skin, it would bring my scalp back to neutral and leave me with cleaner hair for longer. And for someone with a dry scalp, it would exfoliate away flakes so moisture could better absorb into the skin.

The treatment is complex and luxurious. Frederic started by applying Biologique Recherche's Lotion P50 Capillaire Purifying Scalp Lotion, which smells less like the signature barbecued garbage scent of P50 OG and more like ACV. Both formulas are high in lactic acid, but the main difference between them is that, in the hair version, breakout-fighting ingredients are either lower in concentration or left out entirely (zits aren't the issue here). Capillaire's formula is also less moisturizing-and unlike P50, which is meant to be left on, Capillaire should be applied on a dry scalp as a first step. The idea is that once the scalp is brought back to neutral, shampoo doesn't have to work as hard to cleanse and conditioner doesn't have to overcompensate with heavy oils or silicones. He massaged it into my hair for 10 to 15 minutes, "to create better blood flow and promote healthy, shiny hair." (I can't confirm what happened in this step because I was too blissed out-if anything, you must see Frederic for a scalp massage.)

After rinsing it out, Frederic applied a mask (the reparative Masque Biologique Capillaire), and then followed that with VIP O2, one of three shampoos available in the line to address specific hair concerns. It's the most "balancing" of the three-my hair tends to be oily near the scalp but dry at the ends, and gentle, creamy VIP O2 cleaned the top without stripping the bottom. The formula is similar to BR's skincare range of the same name, if you're into that. Frederic chased the shampoo with Baume Capillaire Conditioner, and I was done in the sink. The last step was a spritz of Biologique Recherche's Lotion Keractive Conditioner. "It contains highly active ingredients including nettle yeast, horsetail and birch bark extract, cider vinegar, and vitamin B5," Frederic explained, presumably in an effort to distract me from the downright rancid smelling liquid being pumped onto my freshly-washed strands. You'd think the smelliest product wouldn't be the only leave-in one, but no. If that were true, it wouldn't be Biologique-a brand for which odorous and beautiful go hand in hand. He finished with a classic blowout, and the scent only lingered slightly after we were through.

My hair felt squeaky clean, but the real proof of services rendered arrived three days later when my hair was still clean-no signs of grease or a need for dry shampoo. "Everyone should go for a scalp treatment from time to time," Frederic had told me. "After multiple treatments the pH of your scalp will be more balanced, and oily or dry strands will be alleviated." Treatments I can do at home, by the way, with my own bottle of P50 Capillaire. For nearly the same price per ounce as the face version, it's another chance for true Biologique purists to sing the P50 gospel.

-Ali Oshinsky