Whether in your local gym or on your TikTok feed, l-tyrosine seems to be a pretty hot topic these days. And considering the natural energy-booster’s impressive benefits, we’re not surprised.

Not familiar with the trend? We’ve got you covered. Consider this your guide to how l-tyrosine works so you can decide if it’s worthy of a spot in your supplement stack.

What Is L-Tyrosine?

Tyrosine, or l-tyrosine, is one of the 20 amino acids that make up the proteins in our bodies. Unlike certain other aminos, like lysine and histidine, tyrosine is considered “non-essential,” meaning that we don’t necessarily have to get it through diet because our body can produce it from the essential amino acid phenylalanine, explains The Vitamin Shoppe nutritionist Rebekah Blakely, R.D.N.

While it may be non-essential, we can take in l-tyrosine from foods, particularly those high in protein, notes Roger E. Adams, Ph.D., doctor of nutrition and owner of eatrightfitness. (Think poultry, fish, beef, pork, soy, dairy foods, nuts, and seeds.)

The benefits of l-tyrosine

One of the most talked-about benefits of this amino acid is its ability to increase mental focus and sharpness. How does it do this? Well, l-tyrosine is a key player in the production of three neurotransmitters: epinephrine (more commonly known as adrenaline), norepinephrine (which works with epinephrine to increase heart rate amidst stress), and dopamine (which plays a role in how we perceive pleasure), Adams explains. 

There’s plenty of research to support l-tyrosine’s ability to boost mental performance during certain cognitive tasks. One study published in Frontiers in Behavioral Neuroscience, for instance, found that it helped improve the memory of workers performing a mentally arduous task. 

Read More: What Causes Brain Fog—And What Can You Do About It?

Another study published in the peer-reviewed journal Acta Psychiatrica Scandinavica found that tyrosine can be helpful for those dealing with low mood since it boosts the production of the feel-good neurotransmitter dopamine. 

Should you supplement with l-tyrosine?

If you’re dealing with a short-term stressful situation (like a big work deadline, a serious case of writer’s block, or an important personal project), you may want to consider supplemental l-tyrosine, says Blakely. “Tyrosine can potentially preserve memory, boost mental clarity, and help you deal with symptoms of acute stress, such as sleep deprivation or working through a challenging task,” she says.

She also recommends l-tyrosine for people who struggle with mood issues, so long as their doctor gives them the thumbs up. 

And then there are people who may need to supplement with l-tyrosine. For those who have a serious condition called PKU (phenylketonuria) and cannot process phenylalanine, for example, tyrosine is critical, Adams says.

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But l-tyrosine isn’t for everyone. According to Josh Axe, D.N.M., C.N.S., D.C., founder of Ancient Nutrition and member of The Vitamin Shoppe Wellness Council, people with hyperthyroidism should not take l-tyrosine supplements since they can interact with thyroid hormones and medications. The amino acid actually contributes to the production of thyroid hormones, so those with any thyroid concerns should really double-check before taking it.

“The supplement may also interact with a medication called Levodopa, which is used to treat Parkinson’s disease,” he adds. Consult with your doctor about any prescriptions you take before updating your routine.

Best Practices for supplementing with l-tyrosine

If you’ve gotten the go-ahead from your healthcare provider to try l-tyrosine, know this: While it’s generally recognized as safe, consuming large doses for an extended period of time may impact your absorption of other amino acids. “Taking these supplements for three months or less is recommended, as there isn’t enough evidence to report that long-term use is safe, especially when taken in large amounts,” Axe says. 

The recommended daily amount of l-tyrosine varies greatly—from anywhere between 500 and 3,000 milligrams. That said, “most supplements contain around 500 milligrams and recommend one or two daily doses,” Blakely says. Not sure where to start? Try The Vitamin Shoppe brand L-Tyrosine, which offers 500 milligrams per serving.

Since l-tyrosine helps keep you alert, it may interfere with sleep if taken later in the day, so Axe recommends supplementing in the morning. 

Also worth noting: “Some people experience side effects from l-tyrosine supplements, including headaches, nausea, and heartburn,” he says. “If you notice any of these issues, it’s best to discontinue use.”