One of the many things you can see on TikTok right now? Videos of people dipping their fingers into a white substance and then rubbing it on their gums for fast absorption. Nope, it's not an illegal drug but a supplement: l-glutamine.
Most users are claiming l-glutamine aids in weight loss by helping to reduce sugar cravings. Nutritionist Leanne Ely (@SavingDinner), one of the users who posted a TikTok about the supplement, says she learned the trick from a psychiatrist specializing in addiction. A number of users then commented on her video, claiming that the supplement has worked for them, helping them to stop vaping or lose weight.
But is l-glutamine the miracle powder TikTok users say it is? To find out, POPSUGAR spoke with Lorraine Kearney, registered dietitian, nutritionist, and CEO of New York City Nutrition, about whether l-glutamine can actually help you lose weight, cut sugar cravings, or even deal with addiction - and what to do instead.
What Is L-Glutamine?
Glutamine is a type of amino acid (the building blocks of protein), and the most abundant one in the human body, according to Mount Sinai Hospital. L-glutamine is essentially the same; it's just the form of glutamine that's found in food and supplements. The human body can produce glutamine itself, and it's also found in many common plant and animal foods, such as meat, poultry, milk, and raw spinach.
In the human body, glutamine is used as a fuel source (specifically for cells lining the intestines) and helps with immune and digestive function, among other things, according to the Canadian Society of Intestinal Research (GI Society). The human body can generally make enough glutamine for its usual needs, according to Mount Sinai; however, in times of high stress (such as after extreme physical exertion, trauma, or an injury) or in people whose bodies are always under more stress (such as those with IBS or immune disorders), there's an increased demand for glutamine, which makes supplementing essential, according to the GI Society.
Can L-Glutamine Supplements Help With Weight Loss or Cravings?
Taking l-glutamine might contribute to weight loss or reducing cravings, but not in the way you think. When you consume l-glutamine, it essentially functions like any other protein. Protein is a great nutrient for weight loss because it digests somewhat slowly, which helps keep you full longer, according to Kearney. Because you feel full for longer, you might be less likely to experience cravings or grab a snack and instead wait until your next meal.
In general, there's no magic supplement that will help you lose weight fast, Kearney says, even though TikTok can make it appear that way. "We don't see behind the scenes," she says. "We don't see them working out or switching up their diet, so when they add in a supplement, it's easy to assume that it's doing all the work."
As for rubbing it on your gums? It's true that the powder form of the supplement can be absorbed faster or more efficiently if you place it under your tongue. However, Kearney recommends ingesting it with fluid (i.e. mixed with water) to score the gastrointestinal benefits of the nutrient.
What Can You Do to Curb Cravings Instead?
Cravings aren't inherently bad - they can be a way for your body to let you know it needs something. When you're hungry, the hormone ghrelin signals to the brain that you need food. Typically, we gravitate towards sugar because it's digested faster than protein and fat and our body is telling us it wants something it can metabolize and use quickly, Kearney explains.
"Sugar cravings typically stem from one of three reasons," Kearney says. "Either you wait too long to eat between meals, so your blood sugar drops; you consume a higher-carb diet which metabolizes faster, therefore, you're hungry quicker; or it's an emotional reaction."
Combining protein, fiber, and healthy fats - all of which digest slowly and provide vital nutrients - can help keep you full for longer, which means your blood sugar is more stable and will therefore result in fewer sugar cravings, Kearney says. You can also introduce l-glutamine naturally through foods rich in protein like chicken, fish, and vegetables like spinach and peas.
As for the emotional reaction? Well, when you're under stress, your body secretes cortisol, aka the "stress hormone." This cortisol surge can make you crave sugary or fatty foods because your body thinks it needs fuel to fight whatever's causing the stress, according to the Cleveland Clinic. These foods also seem to reduce stress-related responses and emotions, making you feel better, according to Harvard Health Publishing.
Does L-Glutamine Help With Addiction Recovery?
This TikTok claim actually checks out. People who are recovering from significant stress or a serious illness - like an addiction - may not be producing enough l-glutamine on their own, and as such, can benefit from supplementing the nutrient, per the GI Society.
For example, a 2011 study found that abstinence from alcohol was considered a major stressor for patients detoxing, and it resulted in low levels of the "feel-good" neurotransmitter dopamine. The study found that amino-acid supplements including l-glutamine helped replenish the lack of these neurotransmitters, which in turn helped with symptoms of alcohol withdrawal.
Indeed, the comments on l-glutamine TikTok videos are filled with stories of loved ones quitting smoking and other addictive habits by introducing this supplement into their recovery.
The Takeaway: Don't Start Supplementing L-Glutamine Just Yet
Ultimately, your overall eating habits have a much bigger impact on weight loss than any single supplement can. L-glutamine likely won't do much on its own, but alongside a proper diet, it may help with weight-loss efforts, Kearney says. And if you're dealing with intense sugar cravings or thinking of using l-glutamine to help overcome addiction, consider chatting with your medical provider or a registered dietitian who can guide you.
Supplements aren't regulated by the Food and Drug Administration as drugs, so it's always important to do as much research as possible on a supplement and talk to a health professional before you take something new - especially, Kearney stresses, if you have kidney or liver disease, as l-glutamine supplements can worsen symptoms. Also, for the record, l-glutamine should always be taken as a supplement and not a substitute for meals.
Above all, remember that no one-size-fits-all approach is going to help you meet your health goals. As Kearney says, "It always comes down to the individual person."