Every guy knows that he needs ideal levels of testosterone to maximize muscle growth from his hard efforts in the gym. Healthy guys who are training seriously have, essentially, two natural ways to increase testosterone through supplementation:

  1. Take supplements that free existing testosterone that is bound and inactive.
  2. Take supplements that increase your body’s production of testosterone.

In other words, you may already have plenty of testosterone in your system, but much of it isn’t available for muscle-building because it’s bound by sex hormone-binding globulin (SHBG), causing it to float aimlessly in your system. On the other hand, you may be able to increase muscle-building by driving up your body’s ability to produce more T.

M&F’s list of testosterone boosters addresses both situations. You can seek out these supplements as stand alone, or look for products that contain more than one of our recommendations, addressing both ways of boosting your body’s natural level of testosterone so you can maximize muscle building.

1. Avena Sativa

This supplement may sound obscure, but it’s just the scientific name for oats. While eating oatmeal provides its own bodybuilding benefits, this extract from oats provides testosterone-boosting effects. Avena sativa extract has large amounts of avenocosides, the active component that boosts testosterone. This supplement is saponin-based, meaning its benefits come from plant chemicals. It works by releasing bound testosterone, increasing your levels of free testosterone, which supports muscle building.

For best results: Seek out products that provide a 10 to 1 ratio of Avena sativa extract, and take 100-300 mg per day. Split your intake (especially at the higher end) over 2 to 3 doses per day. After you’ve taken Avena sativa for up to eight weeks, give your body a break by taking 2 to 4 weeks off.

2. Fenugreek

This herb is a dynamic testosterone booster, allowing your body to balance and regulate this key male hormone. That’s because fenugreek passes through your liver before it affects your T levels. Once your liver is on board, the saponins (plant chemicals) in fenugreek help increase your body’s free testosterone. This is the type of “T” that your body can use to support muscle building, and fenugreek helps you make the most of your body’s natural levels.

For best results: Take in 500-2000 mg of fenugreek per day, but you should balance this with Tribulus terrestris (discussed below), making sure that you don’t take in more than 2000 mg per day combined, as they work in similar ways.

3. Forskolin

Forskolin comes from the root of the Coleus forskohlii plant. It’s been used for medicinal purposes for centuries, and it’s been used as a fat burner over the past decades. But forskolin is also a testosterone booster. Forskolin works by activating an enzyme, adenylate cyclase, known to increase levels of cyclic adenosine monophosphate (cAMP), which helps regulate energy systems. Increased levels of this enzyme in Leydig cells (found near the testicles), stimulate testosterone production.

For best results: Look for products that are standardized for 20-50 mg per dose, and take this two to three times per day for a total of up to 150 mg of forskolin per day. Note that the amount of forskolin may need to be multiplied by the percent of the extract to compare dosages from one product to another (e.g. 250 mg of a 20% forskolin extract yields 50 mg of forskolin).

4. Tongkat Ali

While this may sound like a formidable pro bodybuilder, boxer or MMA fighter, it’s merely a rainforest plant. However, it still packs quite a punch, boosting testosterone levels by releasing bound testosterone from SHBG. Tongkat ali (aka Eurycoma longifolia) also stimulates the Leydig cells of your testes, which boosts testosterone production. So tongkat ali provides a one-two hit—setting free what you already have while increasing production of more testosterone.

For best results: Take 100-300 mg in the morning; about 30 minutes before training, and before bed. As with other T boosters, take this supplement for up to 8 weeks, and then take a 2- to 4-week break.

5. Tribulus Terristris

This herb, which grows in both Asia and North America, has been used as an aphrodisiac for centuries—no shocker, then, that it boosts your testosterone levels, right? The supplemental form of Tribulus terrestris increases your body’s level of luteinizing hormone (LH), which encourages testosterone production. To get the most from tribulus supplementation, you should seek out products that contain 80% or higher total saponins with 40% prodioscin.

For best results: Take 500-2000 mg per day, divided over two to three doses, taking one about an hour before workouts. After you’ve supplemented tribulus for up to eight weeks, you should give your body break, cycling off for 2 to 4 weeks. Keep total consumption of tribulus and fenugreek (above) within this range, as they work in similar ways.

6. Vitamin D

A vastly underrated testosterone booster, this fat-soluble vitamin provides numerous benefits. When vitamin D is plentiful, studies show that it increases strength. One of the ways it does so is by being converted in your body into an important steroid hormone (1,25-dihydroxyvitamin D). When your body has an abundance of vitamin D, it signals your genes to increase muscle strength and growth. Supplementing vitamin D helps maximize this potential.

For best results: Take 1000 IU of vitamin D3 2 to 3 times per day. This is the most important form of vitamin D for building muscle tissue.