Think back to the last time you were stressed out about something: The racing thoughts, clammy hands, and nervous energy you likely felt were thanks in part to a little hormone called cortisol. While it's normal (and essential) for cortisol levels to rise and fall throughout the day, the hormone shouldn't stay elevated for too long.

Cortisol is the body's main stress hormone, and our adrenal glands naturally release it throughout the day. Just about every organ in the body has receptors that react to cortisol, explains Ian Leber, M.D., the chief medical officer of Sollis Health.

"Cortisol is essential for living. It peaks at the beginning of the day to support getting out of bed and decreases throughout the day to allow 'sleep pressure' to build. Without cortisol, we would lack the motivation to get up and do things," says Shera Raisen, M.D., a physician at concierge primary care center The Lanby.

"Cortisol increases glucose in the bloodstream, enhances your brain's use of glucose, and it also increases the availability of substances that repair tissues," explains dual board-certified doctor Seema Bonney, M.D. This makes us feel more awake, alert, and ready to take action. So it makes sense that any time we're faced with a perceived threat, the adrenals churn out some more cortisol to help all the organs in our body prepare to fight or flee the situation.

The issue is that as cortisol revs our bodies up, it diverts energy away from the processes that aren't essential for the fight-or-flight response, such as digestion and rest.

"Typically, perceived threats pass quickly and the hormone levels return to normal resulting in a return to baseline for those nonessential systems," Bonney explains. However, "when stressors are consistently present and you constantly feel under attack, this fight-or-flight response stays turned on." This is when cortisol can start to negatively affect things like sleep quality, blood sugar balance, immunity, and digestion.

L-theanine is an amino acid that promotes the production of relaxing alpha waves4, which calm down the brain but don't necessarily make us tired. In one 2016 clinical study5 published in the journal Nutrients, those who drank a beverage containing L-theanine and then completed a cognitively stressful task got through it with significantly lower cortisol levels than a placebo group. This calming amino acid is found primarily in green tea, but it can also be taken as a supplement.

In addition to giving your body the right vitamins and minerals and supplementing as needed, here are some other ways that Bonney, Leber, and Raisen recommend keeping stress and cortisol levels in check.

At mindbodygreen, our expert-vetted dietary supplement product selections and recommendations in the supplement space elevate quality, efficacy, innovation, and safety.

Our team ensures that each supplement product is thoughtfully formulated--from the active ingredients to those "Other ingredient" excipients too. We are highly preferential towards clean formulas that are plant-centric (and oftentimes vegan or vegetarian) as well as free of GMOs, gluten, soy, dairy, major food allergens, high-fructose corn syrup, artificial sweeteners, synthetic dyes, and more.

Overall, we recommend products with clean ingredients at efficacious doses in bioactive forms. Whenever possible, we celebrate and elevate plant-origin (i.e., plant-sourced) ingredients from a variety of botanicals.

Ingredient source and innovation are top of mind for our critical reviews and selection of supplement products. We prioritize forward-thinking formulations and delivery formats that are genuinely helpful in transforming your health.

We include supplement brands and products that prioritize quality. This includes robust manufacturing practices and comprehensive purity and potency testing.