Should you really be chugging fulvic acid or smearing it on your face?

No matter where you stand on supplements, it’s not hard to see their appeal. Take fulvic acid, among the latest to hit wellness TikTok. Smoothing it onto your face brightens and evens out skin tone, proponents say, while drinking it boosts immunity. “It is attaching itself to the microorganisms, and it is absorbing all of the bacteria,” says a voiceover set to a video of a TikToker adding black-brown droplets of fulvic acid to a carafe of water. “Video doesn't lie. Just imagine what this could do for your body, you guys.”

If enhancing your skin and immunity were a matter of using the right supplements, why wouldn’t you take them? But according to experts, it’s not that simple (nor could you even confirm the “bacteria absorbing” process described in the TikTok above with the naked eye, but anyway). Here’s their breakdown of fulvic acid and the most popular claims about it.

First things first: What is fulvic acid?

Experts tell me that fulvic acid is a component of humic substances, which form when animal and plant substances decompose. It’s found in soil, compost, and even sewage, explains Camila Martin, a registered dietitian at UW Health.

The antimicrobial, antioxidant activity of a subtype of fulvic acid known as oxifulvic acid makes it especially attractive for skincare, says Cindy Wassef, an assistant professor at the center for dermatology at Rutgers Robert Wood Johnson Medical School. So does its low weight and water solubility. Since our skin consists largely of water, anything water-soluble will be easily absorbed into it, which we want in a skincare product.

Fulvic acid is nothing new, though, Martin points out. Per Healthline, people have been using shilajit — a source of fulvic acid found in the Himalayas and other mountainous regions — for centuries to treat ailments ranging from altitude sickness to asthma.

But “what’s tricky about any therapeutic measure that comes from traditional medicine is that rarely does it come with verified benefits or recommendations of dosage or efficacy,” she says. She suspects that, as with many supplements, social media glommed onto promising findings of a study of fulvic acid conducted in, say, a test tube, “before it was actually able to go through the research process and then tested safely in humans.”

Can fulvic acid brighten and even out your skin tone?

A bunch of TikToks feature people massaging Inkey List’s fulvic-acid based brightening cleanser into their skin, crediting it for their glowy, even complexions. But how much research do we have to back up this claim?

Not a whole lot, according to Wassef. Studies in lab-grown cells and a small group of people provide “some evidence” that fulvic acid’s purported anti-inflammatory properties can alleviate eczema, she says. But there are even fewer studies on whether it can help reduce hyperpigmentation (a.k.a., dark spots) or brighten skin. “Under the microscope, it looks like it can work,” she says, “but how it has played out in people’s day-to-day life — we haven’t yet reached that point of research.”

In contrast, around two decades’ worth of rigorous human studies show that vitamin C can brighten and even out skin tone, Wassef points out. Researchers followed participants for months, imaging and even taking biopsies of their skin to assess whether their dark spots lightened, for example, or whether their skin actually absorbed the vitamin C. “There definitely is nothing to that same degree quite yet for fulvic acid,” she says.

And while we have enough data on vitamin C to set a standard concentration and formulation for the best results, we’re not there yet for fulvic acid. We don’t know the concentration needed to lighten dark spots, she notes, or whether it would differ from the one used for eczema. Also, while some tout fulvic acid as gentler than vitamin C, “it could be gentler because the concentration you’re using is maybe not effective,” Wassef says.

That said, she believes the early data on fulvic acid is promising. “Perhaps it’ll be an option in the future for people to use in addition to vitamin C or instead of vitamin C,” she says.

Can fulvic acid improve your immunity?

There’s “very little evidence” that fulvic acid can increase your immune system’s ability to stave off infectious diseases, Martin tells me. She explains that many of the studies on fulvic acid and immunity have come out only within the past five years or so. “That’s very, very new in the world of research” she says.

Scientists have conducted most of the research on fulvic acid in animals and test tubes, she notes, which have yielded mixed results. The few human studies that exist consisted of only a few dozen participants and tended not to represent the population at large. One study in 30 men showed that higher doses of fulvic acid could lead to diarrhea, headaches, and sore throat, she says.

“Even though there might be some things that are promising, it’s in such a small amount and with such a limited participant group that we really can’t extrapolate any information yet to actually recommend anything to the general public,” including what concentration to take, Martin says.

Plus, as buzzy as phrases like “immune enhancing” or “immune boosting” are right now, we can’t conclude whether fulvic acid has these sweeping effects, she adds, since each study has looked at different components of immunity — a specific class of molecules involved in the immune response, for example.

The thing is, we already know what improves immune function, Martin says: eating a healthy, balanced diet and engaging in healthy lifestyle practices like exercise. “That is going to have the biggest impact on our immune health,” she explains. But for any number of reasons, “accomplishing those is easier said than done, so I think lots of times, people are looking for something that’s a quick fix” — something like a supplement.

Okay, but what if I’m still curious about fulvic acid?

Long story short, we don’t have enough evidence to recommend using fulvic acid for skincare or immunity. But if you want to check it out anyway, keep in mind that because the research is still so scant, we still don’t have any guidance on the maximum amount considered safe, Wassef says — or much else, for that matter.

If you want to incorporate fulvic acid into your skincare routine, she suggests first dabbing a small amount on a discreet spot (in case you experience an irritation or allergy), like behind your ear, for a week or so. “I would kind of be reasonable with the expectations, because we don’t really know what to expect,” she says.

And if you want to stir fulvic acid into your water à la Kylie Jenner or other influencers, Martin recommends talking with a healthcare provider who really knows your situation and other medical conditions, and starting out with a smaller dose. Remember that supplement companies don’t need to meet the same safety and efficacy standards that drug makers do. What’s more, because fulvic acid a relatively new product and the result of decomposition, contamination is a real possibility. “We know that soil can carry, depending on the area, a high amount of arsenic or heavy metals,” Martin says. To minimize this risk, she suggests looking for products with NSF International and USP certifications.

It makes sense that some TikTokers seem abundantly confident in the benefits of fulvic acid — especially if they’re wellness influencers who may stand to profit if you choose to buy it. As a consumer, though, you’ll definitely want to adopt more of a “buyer beware” attitude.