You don’t need a medical degree to conclude that a tired brain functions at a lower level than a well-rested one, but it may come as a slight surprise that the same thing can be said about sleep-deprived skin.

In fact, natural beauty expert Merrady Wickes went so far as to tell Well+Good that not getting enough shut-eye “lowers your [skin’s] natural moisture levels, slows down your cell turnover, and just makes you feel awful.” (I mean, that last one we’re definitely well-aware of.) Right about now, you might be thinking these are exactly the kinds of drawbacks that would justify downing a few quadruple espressos. Unfortunately, caffeine may not be the skin savior you’re hoping for—at least when guzzled in excess.

First and foremost, it’s important to highlight that caffeine is caffeine, regardless of the source of it (i.e. coffee, tea, energy drinks, and so on). Dermatologist and founder of Dr. Dennis Gross Skincare, Dennis Gross, MD, underlines that what does count in terms of maintaining healthy skin, however, is how much is consumed. “There are really no negative consequences [for your skin] if you stick to one 12-ounce cup of coffee each day,” says Dr. Gross. “However, if consumed in excess, you can experience some negative side effects.” (Don’t worry: Caffeine has some skin-boosting benefits to offer, too. More on that later!)

Caffeine and skin: the drawbacks

1. Caffeine can be dehydrating

“Caffeine is a diuretic, meaning it promotes diuresis, the increased production of urine, which can lead to dehydration,” says Dr. Gross. “When you’re dehydrated, skin can appear dry and dull.”

Melissa Rifkin, MS, RD, CDN goes on to suggest that, because of its diuretic impact, always be sure you’re hydrating throughout the day when consuming caffeine. “The best way to check hydration status is by the color of your urine: When it’s light yellow, that indicates adequate hydration,” she says.

2. Caffeine can disrupted sleep, which may mean tired-looking skin

Drinking caffeine late into the afternoon can negatively affect your sleep cycle. “Consuming caffeine after 4 p.m. can affect sleep even hours later,” says Dr. Gross. “It can cause insomnia or disrupt restful REM sleep, which ultimately acts as a stressor on our nervous system and can cause under-eye circles and puffiness because of exhaustion.”

3. Caffeine can trigger rosacea

Keep in mind that not everyone responds to caffeine in the same way. There are some people that are sensitive to caffeine—even one cup of coffee might be too much—and their skin will react more strongly to caffeine consumption than those with a high caffeine tolerance. “Caffeine is a known trigger for rosacea, especially for those who are sensitive to it. This can cause swelling and redness, just like other known triggers like red wine and spicy foods,” says Dr. Gross.

4. Caffeine can exacerbate internal stress, which may lead to dull or oily skin

According to Dr. Gross, overconsumption of caffeine can exacerbate agitation and nervousness because it can cause a spike in cortisol and adrenaline levels, adding to the stress that people experience in their daily lives. “Even if not excessively consumed, caffeine can aggravate the physiological events that happen in the body when stressed. Your body prioritizes blood flow to vital organs and away from skin, which results in sallowness, dullness, under-eye circles and can even cause oily skin.”

Caffeine and skin are a beneficial pair when used topically

Funny enough, although there are some negative effects that can happen when caffeine is consumed, it has quite a few topical benefits. “This is because applying caffeine topically does not get into the bloodstream like it does when it’s ingested,” says Dr. Gross. “In fact, caffeine can be an effective ingredient in skin care, particularly for eye products and products targeting redness. It does an excellent job reducing puffiness, redness and inflammation.”

1. Caffeine has anti-inflammatory benefits when applied topically

“Caffeine is a vasoconstrictor meaning it constricts blood vessels, so applying caffeine directly to skin can reduce red, puffy, and/or inflamed skin,” says Dr. Gross.

2. Caffeine has antioxidant benefits when applied topically

“Coffee is a great source of antioxidants therefore, topically, it can reduce free radical damage and protect skin from future damage,” says Dr. Gross.

Before you total ditch your beloved morning oat milk latte, Ryan Andrews, MS, MA, RD, RYT, CSCS, the principal nutritionist and adviser for Precision Nutrition underlines that it’s important to bear in mind that we consume many compounds every single day through our diet, and there’s a wide variety of responses to these compounds. “Caffeine is no different: Some people are faster or slower metabolizers of caffeine, which will influence what type of impact caffeine has,” he says. Like most things in life, the relationship between caffeine and skin can be boiled down to everyone’s favorite adage: Everything in moderation.

If you are trying to cut back on caffeine, try swapping out your regular morning brew for this delicious (and jitter-free) herbal drink: