During times of stress, the adrenal gland produces hormones, such as epinephrine (adrenalin) and cortisol, which regulate the stress response. The activities of stress hormones enhance both mental and physical capacities, but over long periods of time, stress is extremely damaging to the body. If stress is not alleviated, it can cause chronic immune suppression, digestive difficulties, malnutrition and insomnia.

The best relief for stress is, of course, the resolution of its cause. But a number of supplements can have a calming effect, or help the body better deal with lowered immune and digestive function. Multivitamin and mineral supplements taken during the day have been reported to have a calming effect, and provide nutrition to the body that may be lacking as a result of the stress response. Vitamin B complex is believed to enhance the activity of the immune system and improve the body's ability to withstand stressful conditions. Preliminary evidence suggests that vitamin C might reduce blood pressure and subjective symptoms during psychological or mental stress.

Many herbs are recommended because they promote relaxation. Passion fruit and valerian, when taken together, produce a mild sedative effect, and are much safer than pharmaceutical sedatives. Members of the ginseng family are also considered to be helpful for stress relief. Asian ginseng is thought to improve mental performance and balance the stress response. In addition to those effects, Siberian ginseng promotes immune function and stamina. Kava has been found to have anxiolytic and sedative effects. St. John's wort will be helpful if stress is accompanied by mild depression. Melatonin might be beneficial for insomnia connected with the stress.