Billie Eilish winds down from the adrenaline rush of performing with an all-encompassing 13-step beauty routine. The "Happier Than Ever" singer walked viewers through her post-show nighttime routine in a video for Vogue.

A theme: Eilish is a fan of a few cult favorite products, which she uses religiously. For one thing, she uses Olaplex No. 6 Bond Smoother "every single time" she washes her hair, and includes other products from the brand in her routine.

The 20-year-old singe has also found that Aquaphor Healing Ointment is worth the hype, going as far as calling it the "love of [her] life" in the video. She carries it with her "at all times, 24/7," she says in the clip. "It doesn't matter where I am. It doesn't matter who I'm with. It doesn't matter what I'm doing. I have this in my pocket and I have six more in my bag, always."

The reason Eilish always keeps the product on hand is that she's found it conditions her lips without the sticky finish of a lip gloss. "This is my lip gloss," she says in the video. "I don't use anything else, if I do it's on top of this and it's just for like a shine. I'm not really a big fan of lip glosses because they are sticky and then they taste weird and then they get in my throat and I can't sing very well when there's a weird taste in my throat." (Related: The Best Lip Balms to Rescue Your Chapped Lips)

Chances are this is far from the first time you've heard about Aquaphor Healing Ointment. The drugstore classic has other devoted celebrity fans, including Beyoncé, Zendaya, and Ashley Graham. It even played a role in Meghan Markle's wedding makeup look, with Markle's makeup artist Daniel Martin using the product as a highlighter.

Aquaphor Healing Ointment is also a common dermatologist rec — doctors have included it amongst their favorite drugstore products and Target finds. That's because the product contains ingredients that both draw moisture to the skin and lock in that moisture. "Panthenol acts as a humectant," Rachel Maiman, M.D., board-certified dermatologist at Marmur Medical, previously told Shape. "When you pair the function of a humectant with the moisture-preserving properties of petrolatum, you are left with a highly effective combination of ingredients that both optimizes water content and locks it in where it's needed."

Buy It: Aquaphor Healing Ointment, $10, amazon.com

While Eilish makes a convincing case for using Aquaphor Healing Ointment to prevent dry lips, it's also popular for treating cracked heels, slugging (using an occlusive product as the final step of your skin care), and promoting wound healing. Between the product's versatility, popularity, and $10 price tag, it seems like Eilish is onto something.