Improved concentration, better learning abilities and sharper memory -- these are all components of mental alertness. Some supplements have been shown to improve aspects of mental alertness, although study results have been mixed. Supplements may not work the same in everyone. Before you take any supplements, talk with your doctor about concerns you may have about your alertness and whether these supplements may be of any benefit.

Take 200mg of Asian ginseng standardized extract capsules, 1 to 3 times a day, suggests the University of Maryland. These supplements should be standardized to contain 4 to 5 percent ginsenosides. Asian ginseng is said to boost alertness, improve concentration and memory, and may improve learning abilities.

Take a ginkgo biloba supplement. Talk with your healthcare provider about a safe dosage for you. Follow the dosing instructions on the package. According to Drugs.com, multiple studies have found that ginkgo biloba helps improves memory, learning retention and visual processing, all of which are involved with mental alertness.

Use rosemary essential oil as an aromatherapy supplement to boost mental alertness and memory. The University of Maryland states that people who inhaled rosemary had reduced anxiety. The herb is often used to help improve concentration as well.

Take a taurine supplement. Mayo Clinic states that supplemental doses up to 3,000mg of this amino acid have been found to be safe, but ask your physician what dose is appropriate and safe for you. Taurine has been reported to improve mental performance when combined with caffeine, but study results are mixed.