What Is a Niacin Flushing Drink and Why Does Katy Perry Drink One Every Morning?

In a recent interview with the Wall Street Journal, singer Katy Perry gave details about what a typical weekday morning looks like in her house. And as many parents of toddlers can attest, there's plenty of play time, reading, and running late to her workouts involved — moms everywhere just gave a collective nod and sigh, because, #momlife.

The pop queen also shared that she makes it a priority to have breakfast with her fiancé, Orlando Bloom, and the couple's 1-year-old daughter, Daisy Dove. And while all of that sounds like a pretty normal morning routine, Perry revealed that the megawatt couple "drink a couple strange drinks or healthy concoctions in the morning" prior to their AM coffee. "We drink a niacin flushing drink, which makes us all red and gets the blood moving. Sometimes we'll have celery juice, it just gets the movements going. We need all the help we can get," she said.

Okay, a couple of morning juices sounds pretty standard, but if you're wondering what the heck a niacin flushing drink is (and why these two A-listers are drinking it), read on.

What Is Niacin and Why Would You Supplement It?

Here's the 411 on this vitamin-rich "concoction," according to Vivek Cherian, M.D., a Chicago-based internal medicine physician.

"Niacin is a form of vitamin B, specifically Vitamin B3, and it's a water-soluble vitamin," says Dr. Cherian, which means it is dissolved in water and absorbed directly into the bloodstream during digestion for immediate use, unlike fat-soluble vitamins, which travel through the small intestines and are distributed through the body in the bloodstream by way of fat cells. (Ah, biology.) Since water-soluble vitamins aren't stored in the body, it's important to get enough of them through a diverse, healthy diet so your body can function normally.

Niacin — like the other B vitamins — plays an important role in turning food into energy for the body, says Dr. Cherian. It's found in plenty of foods (both plant- and animal-derived) — including poultry, fish, brown rice, nuts and seeds, and bananas — and as such, niacin deficiency is rare, according to the Harvard T.H. Chan School of Public Health. (For context, adult women need 14mg of niacin a day for proper function, while pregnant women need a bit more, at 18 mg, per the National Institutes of Health. A 3oz serving of grilled chicken breast, for example, will give you 10.3mg of niacin, and a cup of cooked brown rice serves up 5.2mg, which is why it's easy to get in a full serving through your everyday food picks.)

"Niacin is available as a supplement in the form of nicotinic acid or nicotinamide, and typically comes in a powder that you can mix with water," said Dr. Cherian. Nicotinic acid has primarily been used to treat high cholesterol levels, he says, but it's rare these days, after a 2011 study published in the New England Journal of Medicine found that niacin didn't provide enough benefit to patients with high cholesterol. (While you're here, read more about cholesterol and why getting enough good fats is crucial for your heart health.)

Other than that, "niacin may also help lower your blood pressure, promote brain health, and help prevent certain skin cancers," he says, "but the studies and data are mixed." Meaning, there's no clear, scientific link between niacin and those perks.

What Is a Niacin Flushing Drink?

Okay, so what exactly is a niacin flushing drink? And why are Perry and Bloom sitting at the kitchen table with red faces after drinking it?

As mentioned above, when mixed in water as a powdered form, niacin becomes a drinkable supplement. And even if it sounds bonkers, getting a ruddy face from drinking niacin is common and to be expected, says Dr. Cherian. "Niacin flush is actually a quite common side effect of taking high doses of supplemental niacin," he says. It happens because niacin causes the small blood vessels in your skin to dilate, which increases blood flow to the skin's surface. (FYI, you may have also seen something called niacinamide in the skin-care aisle, as it comes with tons of complexion benefits.)

"This will typically start around 15 minutes after taking the supplement and start tapering off around the 1 hour mark," he says. "Common affected areas include the upper body and face. You may experience tingling or a burning sensation as well as reddening of the skin (almost appearing like sunburn). Your skin may also feel warm to touch."

If that sounds scary AF, fear not. "The good news is that it is harmless, but some of the side effects can be uncomfortable," says Dr. Cherian.

Is Taking Niacin Safe and/or Effective?

Perry didn't elaborate on exactly why she and Bloom supplement niacin, or if they're doing so under a doctor's supervision. That said, if you're interested in boosting niacin or other B vitamins, it's probably much safer to up your intake of vitamin-rich foods, including dark, leafy greens, nuts, seeds, legumes, fortified breads and cereals, and other veggies, versus reaching for a powder or pill.

As for following in Perry and Bloom's footsteps, Dr. Cherian says, "I don't know if it's effective, but I would be weary of accidentally overdosing," particularly if you're supplementing without a doctor's recommendation. "Some symptoms of overdosing on niacin include abdominal pain, nausea and vomiting, and a rapid heartbeat, among others. What's more concerning is that niacin has been linked to strokes and liver damage, so you want to be extremely cautious about taking high amounts of niacin for any reason."

Doses over 500mg/day can cause the aforementioned unpleasant side effects, while doses of 1,000mg/day can lead to severe side effects, including dangerously low blood pressure, blurred or impaired vision, nausea, heartburn, and abdominal pain, according to the NIH. Supplements with 30mg or more of nicotinic acid can cause the flush, and given that some niacin supplements contain up to 1,000-2,000mg of niacin, it's clear why flushing from niacin supplements is common, and other potential side effects are a risk. (And reminder that supplements aren't regulated by the Food and Drug Administration, meaning you don't always know what you're getting.)

The TL:DR here — check in with your doctor before starting any vitamins or supplements, no matter how popular and harmless they might seem. It's just not worth the risk to try something that isn't quite right for you and your health.