Lycopene, found primarily in tomatoes, is a member of the carotenoid family, which includes beta-carotene and similar compounds found naturally in food, and has potent antioxidant capabilities. Tomatoes and tomato-containing foods are high in lycopene. In the Harvard study, the only tomato-based food that did not correlate with protection was tomato juice. In an unblinded, controlled trial, lycopene supplementation, but not tomato juice, effectively increased the body’s lycopene stores. [Am J Clin Nutr 1999;70: pp.490-4] These studies suggest that the lycopene present in tomato juice is poorly absorbed. However, other research indicates that significant amounts of lycopene from tomato juice can, in fact, be absorbed. [Am J Clin Nutr 1998;68: pp.1187-95] Other foods that contain lycopene include watermelon, pink grapefruit, and guava.

Tomatoes provide the best natural source of lycopene, but the benefits you receive from tomatoes may depend on how they're prepared. According to research from Cornell University, the body absorbs lycopene more efficiently (and benefits from a higher antioxidant activity) when tomatoes are cooked, as opposed to eating them raw.

Dosage
The daily supplemental intake of 5mg lycopene is comparable to the usual daily carotenoid intake. The ideal intake of lycopene is currently unknown; however, the men in the Harvard study with the greatest protection against cancer consumed at least 6.5mg per day. Doses of up to 30mg daily by mouth have been reported in scientific studies.

The bioavailability of lycopene varies significantly depending on the administered matrix. Lycopene from tomato oleoresin capsules and tomato juice (processed tomatoes) was better absorbed from the intestine than lycopene from raw tomatoes. [Euro J Nutr 1999, 38:3 pp.118-125]

Reactions
No adverse effects have been reported with the use of lycopene.