Photo: Studio Rauzier Riviere/Courtesy of Biologique Recherche

If there were a Hogwarts for beauty, Dr. Allouche would be the Defense Against the Dark Arts teacher always shouting “Constant vigilance!” To him, your skin is a gentle princess who must be protected by a fire-breathing dragon from the free radicals of the world. His skin-care line, Biologique Recherche, offers that protection. At press events, Dr. Allouche is prone to shouting his skin-protectionist sentiments, punctuated by gesticulations and slams of his fist against tables. “Your skin is but a sandweech of water and lipids! It must be protected!” he explained at a recent event, smashing his hands together.

Biologique Recherche is the opposite of touchy-feely. It doesn’t talk about healing ingredients or chakras or unity or organics. The packaging looks like something your beauty-obsessed aunt had in the ‘80s, with a typeface last seen on floppy disks. And yet the product has inspired a cultlike following, specifically its P50 lotion, which some netizens deem “Jesus in a Bottle.”

When interviewed about her skin routine by the New York Times, the writer Jill Kargman claimed the product made her look fetuslike and blackhead-free. Meenal Mistry raved on Twitter about having used it for ten years. Makeup artist Gucci Westman enthused about the entire product line to a group of beauty editors, proclaiming it “wonderful” but also admitting that it smells “so, so, so bad.”

P50 does smell very bad. Emily Weiss said it gave her a scent her boyfriend dubbed “trash face.” Westman compared the scent to sour breast milk. It just stinks, not in a smelly-so-good way like blue cheese. And yes, unbelievably, this acrid-smelling, unadulterated, non-perfume additive formula is French.

Despite these detriments, the P50 lotion is the hero product of the line and a rare, new beauty category hybrid. It’s an exfoliating toner that neutralizes the PH in your skin, and is made up of lactic acid, witch hazel, and many vitamins. It makes your skin look brighter, cleaner, and clearer — even if you had largely clear skin to begin with. It gives you the kind of skin that makes you consider taking a #nomakeup selfie for the first time in your life. I first saw its effect following a P50-heavy facial at the Core Club administered by Dr. Allouche. In between facial administrations, I took the time to ask Dr. Allouche a few questions about his line’s hero product and what makes it so effective.

People have called P50 “Jesus in a Bottle.” What makes it so effective?

To tell you the truth, I wasn’t aware of such a name for the P50; however, the great popularity of this “potion in a lotion” comes from its effectiveness and extremely quick and long-lasting results.

Dr. Allouche. Photo: Courtesy of Biologique Recherche

Why do we need an exfoliating toner in our beauty routines? Why not just an exfoliating cleanser?

In the early ‘70s, my father and I tried to build a very consistent approach in respect of our core concept, which is made of respect for the skin structure, while enhancing its most noble function. To protect one’s body with integrity, which goes far beyond the mainstream “anti-aging,” there is a fully functional epidemic, which I often call “skin reconditioning.” This is the essential goal.

In order to achieve it, we need to correct or control several epidermis parameters. Lotion P50 is a cornerstone product of the Biologique Recherche system, and is used to boot several epidermal functions. Exfoliation is definitely an important factor, and P50 provides a large amount of anti-free radicals and several vitamins, as well as a powerful moisturizing agent and sebum controller.

How did the idea for P50 develop?

In the early 1970s, lotions containing strong acids were only available for medical professionals and beauticians. My father felt that those kinds of products were too harsh to be used in the salon environment and nothing was really offered in order to relay those aggressive solutions on an everyday basis that helped the natural exfoliation process while reinforcing the epidermis.

So, the idea of creating a new era of products came to his mind. Early in the year 2000, I reformulated P50 by integrating ingredients that helped fight the new challenges the skin was facing, such as increases of interior and external stresses, and the fact that every single person has experienced or will experience an episode of skin sensitivity. The new P50 that I reformulated is packed with even more anti-oxidants and anti-inflammatory plants. And the exfoliation became milder, as I added polyhydroxy acids to the solution.

What is the connection between PH and good skin?

Epidermal PH is usually acid reflecting the good status of the natural moisturizing factor, and the acid mantle of the skin (anti-microbial shield and chemical protection screen). However, the epidermis PH may vary considerably during the day, suffering from different artifacts. Epidermal surface PH is difficult to monitor and not always the best parameter for assessing the health of epidermis.

What makes the skin tingle when using P50?

When the epidermis is unbalanced, patients feel the acidity of the solution, causing the skin-tingling sensation. Once you reach a balance, this sensation will disappear.

What is the meaning of the name P50? Will there one day be a P75 or P100?

The P can be used for potion or peeling (the first name of the product was Lotion P1970, then P50, P50V, and P50W were developed).