From the televangelist busted for hawking a bogus immune-boosting COVID-19 “cure” to Herbal Amy, a company selling herbal coronavirus prevention tinctures for $100 a pop, scammers are having a ball with the pandemic.

According to an April report by the U.S. PIRG Education Fund, the FDA has issued 34 warning letters to groups peddling unproven treatments for COVID-19. And more than half those products claimed immune-boosting or antiviral properties.

This idea of boosting your immune system is appealing for obvious reasons, but the truth is there’s no proof that anything (besides vaccination) actually enhances immune response.

While there’s no magic immune-strengthening potion, we do know that balanced lifestyle habits are associated with proper immune system function. And the good news for you (not so much for the scammers) is that these habits are quite cheap — if not free — to put into action.

We know this is easier said than done, but we put it first for a reason. When you don’t get enough sleep, you have a higher chance of getting sick. And if you do get sick, it’ll probably take you longer to recover.

“Less sleep deprives our immune system of energy, as it is used elsewhere to cope with the health changes related to less sleep,” says Joanne Turner, PhD, vice president for research and a professor at Texas Biomedical Research Institute.

Research suggests that getting enough sleep can also increase the effectiveness of vaccines, lower your risk of infection, and reduce inflammation.

Tips for getting better sleep

You’ll notice we didn’t say “eliminate stress,” because that’s pretty much impossible — and some stress can actually be a positive thing. But too much stress is bad news for your immune system.

While fleeting periods of stress can temporarily decrease the production of immunity cells, chronic stress — lasting months or years — has been shown to have “persistent and severe” consequences for the immune system.

“Excessive stress switches on a lot of hormones,” says Turner. “These hormones can directly or indirectly turn off immune cell function. Chronic stress (ongoing daily stressors) can also lead to chronic low level inflammation that we know reduces how our immune system works.”

Tips for de-stressing

  • Get some oxytocin, platonically or otherwise. A 2015 study found frequent hugs are an antidote to stress and may help protect against infection.
  • Take regular baths. A small 2018 study found that regular bathing was linked to more positive moods than regular showering.
  • Find a creative outlet. In a small 2007 study, people with cancer and depression felt their mood improve after doing weekly art therapy sessions.

The science supporting supplements for immune function is less robust than many supplement companies would have you believe. But vitamin D appears to be beneficial to the immune system.

Vitamin D deficiency, which affects about 1 billion people worldwide, has been linked to autoimmune conditions and increased vulnerability to infections.

If you have a dark complexion, don’t spend much time in direct sunlight, and don’t regularly eat dairy or fatty fish, you’re at an even higher risk of having a vitamin d deficiency.

Word to the wise: Get your vitamin D from food and supplements, not from the sun. Skin cancer is the most common form of cancer in the world, and up to 90 percent of skin cancers are caused by sun exposure.

Tips for safely getting vitamin D

  • Take 600 IU of a vitamin D supplement daily.
  • Eat foods that are high in vitamin D, like milk, mushrooms, and salmon. (See a full list here.)

We still have a lot to learn about how diet affects the immune system, but we know that malnutrition is the most common cause of immunodeficiency in the world.

“Our immune system needs energy to work in the same way that we need energy to go for a run. Our bodies need nutrients to do that work,” says Turner.

It’s important to get as many nutrients as possible from food rather than from supplements, because your body needs the energy provided by the calories in food to survive.

PSA: We made this no-fuss one-day menu packed with nutrients for those days when you need help figuring out how to eat well.

Tips for eating a balanced diet

Washing your hands and avoiding touching your face are the two very best ways you can help your immune system defend you against dangerous pathogens, including COVID-19 (until we get a vaccine, at least).

According to Christopher Lupfer, PhD, an immunologist and assistant professor of biology at Missouri State University, people often get lazy with hygiene because they think living a healthy lifestyle will be enough to protect them.

“Just because you take [vitamins] does not mean you will not get sick,” he says.

How to wash your hands

The 5 steps, according to the CDC:

  • Wet your hands.
  • Lather up — don’t forget about the backs of your hands and under your nails!
  • Scrub all parts of your hands for 20 seconds, which is conveniently the time it takes to sing the chorus to “Jolene” (or the “happy birthday” song).
  • Rinse your hands under running water.
  • Dry your hands with a clean towel.

Vaccines are the only evidence-backed method for stimulating immune function. Yes, the one and only. Despite this, they’re often left out of the immune system conversation.

While there’s no COVID-19 vaccine at the time of this writing, once one is developed, getting vaccinated will be the single most important way to support your immune system.

And while we’re all understandably fixated on COVID-19 right now, it’s still important to stay up on all your immunizations. This will not only decrease your likelihood of going to the hospital (where there’s a higher chance of being exposed to the virus) but also decrease your immune system’s overall workload.

Here’s the CDC’s full list of the vaccines you should have, depending on your age.

As Shayla Love, a senior health reporter at Vice, points out, the popular understanding of the immune system as a militant killing machine that needs “boosting” and “strengthening” is misguided. In fact, an overactive immune response may actually kill you (as it sometimes does in the case of allergic reactions).

The immune system’s ability to be passive and discerning is just as important as its ability to spring into action.

“Our immune system doesn’t attack our food, water, or many particles that are in the air we breathe,” says Turner. “[It’s] educated to ignore things that aren’t dangerous.”

Which is to say, we’re better off conceptualizing the immune system as a web of intricate processes — not unlike a symphony — that depends on balance and harmony to function. We can’t support this complex system by taking one magic pill. Instead, we must give care to our bodies on multiple fronts.

Ginger Wojcik is an assistant editor at Greatist. Follow more of her work on Medium or on Twitter.