The secret to clear, glowy skin? It’s inside you. Actually.

On Thursday, Page Six reported that “Ocean’s 8” stars Cate Blanchett and her pal Sandra Bullock had tried the “penis facial” with luxe NYC aesthetician Georgia Louise.

The Hollywood EGF Facial — a $650 treatment — involves a cleanse, chemical peel, microneedling, an “electrifying” face mask and a so-called “Epidermal Growth Factor (EGF)” — a serum that happens to be derived from the foreskin of Korean newborns. The substance supposedly helps generate collagen and elastin in the skin.

It’s just one of many borderline cannibalistic — and inevitably expensive — beauty products wooing the rich and vain these days.

Massaging your face in blood might sound downright medieval, but that’s the thought behind the “vampire facial,” a beloved treatment of A-list lookers including Cher, Rosie Huntington-Whiteley and Kim Kardashian. For $950 — plus a flight to Germany — Dr. Barbara Sturm will take samples of your blood and formulate them into a cream that’s said to heal skin and boost collagen.

Placentas are regularly recycled by mammals in the wild, but humans have found a far more superficial use for afterbirth. Like our own, the proteins, nutrients and enzymes found in an animal-derived placenta is thought to help promote skin-cell growth, as it does for babies in utero. Judging by the ageless complexion of designer Alexander Wang, who swears by the bizarre ingredient, it’s a safe bet that this beauty trend is here to stay.

“Urine therapy” made a splash, so to speak, thousands of years ago, when it was an ancient Eastern tradition commonly used for myriad purposes. Antibodies found naturally in urine have anti-microbial and anti-inflammatory properties, and can feasibly treat skin ailments such as rashes, burns, dry skin and acne. There’s probably no need to swap your toner for urine (as some have). As it turns out, urea is already widely found in skin-care products.

Technically, we’re not using human breast milk to create colostrum-gel-based products, but the properties of bovine breast milk are very similar to those of our own. Produced by mammals during pregnancy, colostrum supplies antibodies and nutrients to newborns, and now, your aging face. Vitamins found in colostrum gel include soothing and smoothing vitamins E and C, which brighten and boost elasticity.