After baby foreskins and “vampire” blood, this “secret” skin care ingredient was probably inevitable.

With over two decades in the beauty business, celebrity facialist Chelsee Lewis has tailored skin care treatments for celebs including Stella McCartney, Suki Waterhouse and even Goop beauty guru Gwyneth Paltrow to maintain their youthful visages over the years. Now, the UK-based esthetician is revealing some of her “quirky” beauty tricks.

One of her weirder facial suggestions: sperm.

Lewis tells the DailyMail semen is full of the compound spermine, an antioxidant which she claims helps reduce wrinkles, smooths skin and treats blemishes. Intercourse is good for your skin, too, by increasing blood flow and oxygen, and improving circulation to the skin’s surface — hence the post-coital glow.

Of course semen masks aren’t the only bizarre beauty treatment celebrities love right now. Last year PageSix reported that pals Cate Blanchett and Sandra Bullock are fans of the so-called “penis facial,” which involves a face mask featuring the foreskin of newborn Koreans. The “Epidermal Growth Factor (EGF)” supposedly boosts the skin’s collagen and elastin.

Recently, the most macabre of dermal remedies, the “vampire” facial, made headlines when two clients of a New Mexico spa contracted the HIV virus after trying the bloody beauty trick with strangers’ fluids. The way the procedure should work begins with drawing out the patient’s own blood, which the esthetician uses to formulate a bespoke cream.

Lewis also is a fan of another gory treatment: micro-needling. By creating microscopic punctures to the skin — which will leave your face a bit bloodied — the tiny wounds can help your skin look more plump by boosting collagen and elastin up to 400%. It’s also known to stimulate hair growth.