E longifolia is a medicinal plant (family Simaroubaceae) native to Indonesia, Malaysia, Thailand, Vietnam and Laos. The root extract has been found to be the most powerful herbal aphrodisiac . Tongkat ali extracts contain many alkaloids, quassinoids, phenolic compounds, tannins, high-molecular-weight glycoproteins and mucopolysaccharides. The main bioactive compounds are eurycomaoside, eurycolactone, eurycomalactone, eurycomanone and pasakbumin-B. It is considered to be natural ‘Viagra’. It increases sexual desire, and enhances performance and general well-being [17- 19]. In addition to its aphrodisiac effect, other medicinal effects, such as antimalarial, antibacterial, antipyretic, antiulcer and antitumour effects, have been reported [20,21]. Root decoction has been used as a general tonic (18,22]. Laboratory animal studies show that root extract enhances sexual characteristics and performance in rodents [22-25]. In a study involving a boar model, it was found that E longifolia root extract-treated boars increased sperm counts and semen volume; the effect was attributed to increased level of plasma testosterone . Reports also suggest that E longifolia extract reverses the inhibitory effects of estrogen on testosterone production and spermatogenesis in rats . Oral administration of E longifolia extract to inexperienced castrated male rats produced dose-dependent increases in sexual performance . Zakaria et al  found that eurycomanone, a potential bioactive compound in the root extract of E longifolia, induced apoptosis in hepatocarcinoma (Hep G2) cells. Furthermore, their work suggested that eurycomanone was cytotoxic to Hep G2 cells and less toxic to normal Chang’s liver and WLR-68 cells. Tambi and Imran  investigated the effects of water-soluble extract of the root of E longifolia Jack and found that the extract increased semen volume, sperm concentration, percent of normal sperm morphology and sperm motility in male partners of subfertile couples with idiopathic infertility. Supplementation with E longifolia elevated the testosterone levels and upregulated osteoprotegerin gene expression in male Sprague-Dawley rats .
In addition, when research has shown a nutrient such as zinc or niacin to improve sexual function, it's usually in people who are deficient in it. So, before you stock up on over-the-counter nutritional supplements for ED, speak with your doctor. He can test you for deficiencies and steer you toward the most effective and safest way to treat your erectile dysfunction.
If you have symptoms of ED, it’s important to check with your doctor before trying any treatments on your own. This is because ED can be a sign of other health problems. For instance, heart disease or high cholesterol could cause ED symptoms. With a diagnosis, your doctor could recommend a number of steps that would likely improve both your heart health and your ED. These steps include lowering your cholesterol, reducing your weight, or taking medications to unclog your blood vessels.