Flawless skin is a primary beauty ambition—and challenge. While fresh, dewy visages are wholly guaranteed in simple home remedies, skincare routines, and expensive potions, their promises always seem to come up short. Among them is the popular claim that guzzling water is the secret to supple, glowing skin.

Celebrities like Jennifer Aniston and Gabrielle Union swear by H2O as the primary formula for getting their faces camera-ready. Beauty magazines never tire of recommending eight to 10 glasses of water to improve skin appearance, boost the complexion, and even eliminate wrinkles. (Try these tested wrinkle-remover tricks instead.) Although adequate water intake is important for your health, there is little, if any, scientific evidence that proves drinking a lot of water has any skin benefits at all.

A review from Clinics in Dermatology found only one study that had investigated the actual effects of long-term water intake on skin health. Published in the International Journal of Cosmetic Science, they deduced that drinking 2.25 liters of water every day for four weeks altered skin density and thickness, but the exact results were ambiguous and contradictory. While another University of Missouri-Columbia study showed that drinking 500 milliliters of water increased blood flow to the skin, they weren’t able to prove any link to skin appearance.

“The outer layer of skin, the stratum corner is designed to prevent water loss from the skin into the environment and is responsible for the ‘waterproofing’ characteristic of the body,” says Fayne L. Frey, MD, a board-certified dermatologist and specialist in skin barrier function. “And, there are studies that show that in individuals that have low water intake, increasing water intake can increase skin thickness and improve skin hydration.”

But, gulping water to maintain skin hydration is only one part of the equation—and doesn’t necessarily correlate to skin appearance. That depends more on your skin’s ability to hold water.

“In healthy individuals with normal skin thickness, excess water has not been shown to prevent wrinkles, remove grooves, fine lines, or any other sign of aging,” says Dr. Frey.

Dermatologists agree you may be better off applying topical moisturizers. Dr. Frey recommends those that are formulated with appropriate occlusives (that prevent water from evaporating from the skin into the environment) and humectants (ingredients that draw water into the superficial layers of skin).

Joel Schlessinger, MD, dermatologist and RealSelf contributor agrees. “Sipping on water throughout the day is great for your body, but this hydration doesn’t actually reach your skin unless you’re extremely dehydrated,” he said. “Instead, skin is hydrated through one of two different ways: natural oil production or topically applied creams, lotions, and serums.”

Remember—your food intake is just as important for your skin. Sonam Yadav, MD, medical director of Juverne, advises that a good skincare diet with plenty of fat and limited refined carbohydrates will mean less water evaporation from your skin surface.

In essence, drinking excessive water may just result in internal issues, or at best, excess sprints to the bathroom—plus, there is such a thing as drinking too much water, so you’ll want to be careful of that. “Hormones, genetics, lifestyle, diet, fabric choices, exercise, choice of skincare products, and more are all factors that affect your skin and your acne,” says Dr. David Lortscher, MD, dermatologist and co-founder/CEO of Lortscher and Curology. “Therefore, while hydration is important, it simply isn’t the end-all be-all miracle to achieving perfect skin.”