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For over a year, I walked around feeling like my head was underwater. Tasks blurred together; it took longer to think of words. I struggled to follow conversations, and as a result experienced social anxiety for the first time in my life. On bad days, even reading a single sentence required a painful level of focus. I started calling it “brain fog,” though the term felt frustratingly vague, more of a symptom than a diagnosis. Was it just my mental health? Burnout? I’d had COVID—was it from that?

I tried everything: sleep, stretching, meditation, medication. I got blood panels to make sure I was healthy. The doctors I saw looked at me with a shrug. The gist was: We can run more tests if you want, but everything seems fine. It’s probably just anxiety. Try to relax. The fog always returned. I felt doomed.

Then I came across a small study in Bioelectronic Medicine, in which researchers gave nicotine patches, the same ones that smokers use to quit cigarettes, to four long-COVID patients for up to a week. Their cognitive symptoms—things like poor concentration and memory issues—improved dramatically, according to patient surveys. The study was tiny and far from conclusive, but I was desperate and willing to give anything a try.

The patch seemed like a big leap, though. At 7 milligrams of nicotine, it felt like too much for me. I’ve never smoked a cigarette or vaped in my life, so this would be my introduction to the substance. I was also worried about the nausea that some people experience with the patches. So I picked up the lowest-dose nicotine gum I could find: 2 milligrams.

That afternoon, I chewed a piece, feeling a bit ridiculous. I was skeptical that this potential fix would be any different from everything else I’d tried (that is, a bust). But within an hour, something had clicked. The fog didn’t lift entirely, but my brain felt like it had come back online in a way it hadn’t in months. Now, I keep a pack of gum on my desk and another in my bag, just in case. Most mornings, I pop a piece while I’m answering emails or getting ready to write. I take another before social events. Two months in, I still chew one or two pieces a day, and the symptoms have mostly stayed away. Every few weeks I can feel a hint of brain fog creeping back in, but it’s nothing like before. My concentration has skyrocketed. I feel like I have my life back.

To be very clear: Anyone taking nicotine to treat brain fog (like me) is still very much experimenting. There are no protocols or prescribed doses approved by the Food and Drug Administration. The evidence for nicotine’s use in otherwise-healthy people with mild cognitive issues is limited to early studies and anecdotal accounts across long-COVID forums suggesting that for some people, it might help. There is more research on how nicotine may help people with some cognitive disorders, though this, too, is something scientists are still exploring. Overall, it might be accurate to say that nicotine “holds promise” as a potential tool for brain functioning.

Bear with me. You might be thinking, Isn’t nicotine bad? The word carries decades of baggage, mostly thanks to Big Tobacco. And there’s no doubt cigarettes (and even vapes) are terrible for your health. But when divorced from cigarettes and delivered in controlled, slow-release doses, researchers say it can, in fact, be good. “We have found that nicotine patches are useful along a whole spectrum of impairments, like people with ADHD, Alzheimer’s, and people with age-related memory and cognitive impairment,” says Edward Levin, a professor of psychiatry and behavioral sciences at Duke University who studies the effects of nicotine. It has also been shown to help with schizophrenia, Parkinson’s, and depression. However, Levin emphasized that all those uses for nicotine patches—anything other than quitting smoking—are still under investigation. He hopes scientists will know more in the “near future.”

What we know now is that nicotine is a chemical compound that acts on receptors in the brain called nicotinic acetylcholine receptors, or nAChRs. “The word we use is modulate—so they modulate nerve cell–to–nerve cell transmission throughout the brain,” says Paul Newhouse, a professor of psychiatry and pharmacology and the director of the Vanderbilt Center for Cognitive Medicine at Vanderbilt University. ”They have an important role in all sorts of human behaviors and cognitive functions.” Those receptors usually respond to acetylcholine, a neurotransmitter involved in everything from muscle activation to attention. But nicotine can bind to and activate those receptors in much the same way as acetylcholine, essentially mimicking its effects on the brain.

Nicotine’s role in facilitating attention is one of its most well-established functions. “We know that nicotine receptors are involved particularly in attention—so the ability to focus and maintain attention, all of that seems to have an important role for nicotinic signaling,” says Newhouse. “And attention is the front end of memory, right? So without attention, you can’t encode or remember anything.” That’s why it’s promising when it comes to conditions involving memory. In 2012, Newhouse and Levin published a randomized controlled trial showing that short-term nicotine use improved cognitive performance in people with mild cognitive impairment. They’re now wrapping up a larger, multiyear follow-up study looking at the long-term effects of nicotine in this population, with results expected later this year. While this kind of data could help build the case for therapeutic nicotine, doctors currently have no guidelines—and no FDA approval—to prescribe it for anything beyond smoking cessation, so many clinicians probably wouldn’t feel comfortable recommending it just yet.

The research on nicotine’s effects on long COVID is very new compared to other cognitive conditions, and there is yet to be a randomized controlled trial. But Marco Leitzke, who is a guest scientist at the Clinic and Polyclinic at the University of Leipzig in Germany and the researcher behind the initial nicotine and long-COVID study that I read, is optimistic about its potential. “Impaired nAChR function in the human body is the first and only hypothesis that can logically explain and decipher every symptom of long COVID,” he says. Since publishing his findings, he’s continued researching dosing regimens and giving lectures to build awareness around the hypothesis that this is what’s happening with long COVID, and that nicotine can help. But to move from hypothesis to proven treatment, he says, the scientific community urgently needs double-blind, randomized, controlled trials—the gold standard for treatment research—on nicotine therapy for post-acute infection syndromes.

Cigarettes and vapes are bad for your health because of what they do to your lungs, but that’s not the only difference between those vices and therapeutic nicotine. Compared to the near-instant delivery of a cigarette—where nicotine spikes in the brain within seconds—gum and patches release it far more gradually. “With the patch, it comes up to a plateau and stays there all day long,” says Levin. The gum—my delivery system of choice—is a little different, but it also doesn’t deliver the big hit that comes with puffing on a cigarette or a vaping device. “You have a very slow absorption, and it kind of comes to a peak, depending on how long you have it in your mouth, but it’ll gradually dissipate,” he says.

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That slower absorption matters, not just for side effects, but for addiction risk. “Anything that you put in your body has a risk associated with it,” Levin says. “But I would say that the gum and the patches are at the very low end of the risk curve.” A 2021 meta-analysis looked at 608 nonsmokers who were administered the patch and found that no one reported dependence. Still, nicotine isn’t side effect–free. The most common issues for nonsmokers include nausea, dizziness, or (in the case of patches) skin irritation. Many people who tried the patch to manage long-COVID symptoms have reported in forums that they’ve had to stop because it caused vomiting. And nicotine isn’t safe for everyone; Levin specifically warns against use during pregnancy, nursing, and in children due to potential effects on brain development.

There’s another important caveat: More isn’t always better. Over Zoom, Newhouse shows me a U-shaped graph. On the x-axis: dose. On the y-axis: performance. “If you’re not working at the optimal level, then stimulating nicotinic receptors will bring you up to here or closer to here.” He points to the top of the curve, where performance is peaking. That’s the ideal case.

If your brain is already working well, though, nicotine can have the opposite effect. “If you’re right here at the top of the curve, functioning at a high level, if I flog your nicotinic receptors, you’re actually going to have a decline in performance,” he adds. I’ve noticed this in my own nicotine use—on days when I used the gum while already feeling clearheaded, I sometimes felt jittery, not sharper. That was rare, but it reminded me that there is the potential to overdo it.

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So: An article on the internet, like this one, cannot tell you that nicotine is a proven therapy for brain fog, or anything else. But if you do try it, Levin recommends going “low and slow,” and working with a doctor. Newhouse says he regularly fields questions from patients curious about trying nicotine for early Alzheimer’s concerns, though he doesn’t have data on how many physicians are actually discussing it with their patients. Both he and Levin are skeptical that nicotine will ever gain FDA approval for cognitive impairment. There’s simply no financial incentive—nicotine is too cheap, too old, and too unsexy for drug companies to invest in. “If it turns out to work for certain kinds of cognitive problems, then it’s a pretty cheap and easy-to-access treatment,” says Newhouse. “But it’s not without its side effects and risks, too. I mean, there’s no free lunch.”

For me, the uncertainty around nicotine feels like a small price to pay. The gum’s been working, so I haven’t bothered switching to patches. (Why mess with a good thing?) After a year of fog, I’m just glad to feel like myself again.

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