1 | Tribulus terrestris This herb is cultivated in many parts of the world--including the United States, Mexico and Asia--and it is used for treating sexual impotency, as well as for boosting muscle growth. Both of those effects stem from its ability to enhance testosterone levels in the body. Current research indicates that the dominant furostanolic saponin--protodioscin--is the active ingredient in Tribulus that affords it its testosterone-boosting effects.
This steroidal saponin appears to stimulate the release of luteinizing hormone (LH) from the pituitary gland. LH then travels via the bloodstream to the testicles, where it stimulates testosterone production. Protodioscin is also believed to increase dehydroepiandrosterone (DHEA) production by the adrenal glands. This steroid precursor becomes testosterone.
DOSE | Try 500-2,000 milligrams (mg), taken in two or three separate doses. On workout days, take one dose about an hour before you hit the gym. Follow a five-days-on/two-days-off regimen for eight weeks, then take two weeks off before cycling back on. Look for an extract that's standardized to no less than 45% protodioscin.
2 | Fenugreek The fenugreek herb is native to southern Europe, the Mediterranean region and western Asia. It has numerous health benefits, including increased libido, elevated testosterone and increased insulin release. As with Tribulus terrestris, this herb contains a high amount of furostanolic saponins. Therefore, fenugreek extract works in a manner similar to Tribulus--elevating testosterone via increases in the amount of LH and DHEA the body produces. Some bodybuilders report having a better appetite when taking fenugreek extract--a great benefit for hardgainers.
DOSE | Take 500-2,000 mg per day of furostanolic saponins from fenugreek or in combination with other saponin ingredients.
3 | Dioscorea deltoidea This climbing plant grown in Asia is used for numerous purposes--from treating asthma to killing lice. Its high concentration of furostanolic saponins makes it a good supplement for boosting testosterone levels in a manner similar to Tribulus terrestris and fenugreek.
DOSE | The effective dosage of these saponins appears to be 500 to 2,000 mg per day. Newer products are available that combine several types of saponin extracts, such as those from Tribulus terrestris, fenugreek and Dioscorea deltoidea. The benefit is that each may produce a slightly different effect within the body to optimize the amount of testosterone produced. Go for a total of 500-2,000 mg of furostanolic saponins daily--regardless of the sources. Again, follow a five-days-on/two-days-off program for eight weeks, taking two weeks off before using the product again.
4 | Avena sativa Avena sativa is the scientific name for oats. An extract from the plant has the ability to increase testosterone levels by enhancing LH release. Maybe that's why oatmeal is such a bodybuilding staple. A bowl of oatmeal probably doesn't have enough of the active compound avenacosides to give a noticeable boost, but concentrated Avena sativa extract does. Avenacosides are a type of plant saponin similar to furostanolic saponins.
DOSE | The product should supply 100-250 mg of 10:1 Avena sativa extract per dose. Take it once or twice daily, consuming one dose 30-60 minutes before workouts. Follow the same plan as for the other LH boosters: take it in a five-days-on/two-days-off cycle of eight weeks on/two weeks off.
5 | Eurycoma longifolia Jack Also known as tongkat ali, Eurycoma longifolia Jack is a small tree that grows in Southeast Asia. It has a centuries-old history of use as a medicinal herb for treating a variety of conditions, but enhancing libido is its most common use. Eurycoma appears to directly enhance testosterone production by the Leydig's cells of the testes. It frees testosterone from its carrier protein--sex hormone-binding globulin (SHBG)--in blood. When testosterone is bound to SHBG, it is prevented from entering muscle cells. Eurycoma can help release testosterone from SHBG so it can enter muscle cells to induce growth. Research shows that it can lower SHBG by about 30% and increase testosterone levels markedly.
DOSE | Look for products that offer 200-300 mg of 20:1 extract of Eurycoma. Take two or three doses per day. Adhere to a five-days-on/two-days-off regimen for eight weeks followed by a two-week break.
6 | Vitex agnus-castus Vitex agnus-castus is an extract from chasteberry. If you're supplement savvy, you may know that chasteberry is traditionally used as a "female" supplement, because it can ease premenstrual symptoms and other menstrual disorders. The active components in Vitex agnus-castus are known as agnusides, which lessen prolactin. Although prolactin is thought of as a female hormone, like estrogen, even males have some. While you sleep, prolactin levels rise. High amounts of prolactin can decrease testosterone production. Supplementing with Vitex agnus-castus can ensure that your testosterone levels aren't being blunted.
DOSE | Purchase products that offer 200-400 mg of Vitex agnus-castus or chasteberry. Take it just before bedtime in alternating cycles of four to six weeks on and four to six weeks off.
7 | 6-OXO (3, 6, 17-androstenetrione) This oddly named compound helps to limit estrogen levels, thereby maximizing testosterone levels. It binds to aromatase, the enzyme that converts testosterone to estrogen. This essentially destroys the enzyme and helps to maintain testosterone at the expense of excess estrogen.
DOSE | Research has reported a doubling of testosterone levels in men taking 600 mg of 6-OXO daily. To boost your own testosterone and limit estrogen, take 6-OXO one to three times a day for a total of 600 mg. Follow a regimen of alternating cycles of four to six weeks on and four to six weeks off.
8 | ZMA In research studies, this combination of zinc and magnesium aspartate plus vitamin [B.sub.6] has been shown to increase anabolic hormone levels, namely testosterone and insulinlike growth factor-1 (IGF-1). In hard-training athletes, zinc and magnesium tend to be suppressed. It's wise to protect your levels of those minerals (and, in turn, your hormones) with a ZMA supplement. ZMA can also enhance sleep quality, which improves muscle recovery.
DOSE | Most ZMA supplements provide 30 mg of zinc, 450 mg of magnesium and about 11 mg of vitamin [B.sub.6]. Take one dose on an empty stomach 30-60 minutes before bedtime.