Testosterone science: how to increase testosterone naturally

3,000 words on increasing testosterone naturally. Reading time: ~11 minutes.

2 calculators/quizzes included:
Zinc intake calculator (Jump there)
Testosterone potential quiz (Jump there)

Did you ever wonder whether you’re leaving potential on the table because your testosterone levels are sub-optimal?

Do you feel like you have symptoms seen with low testosterone levels?

Testosterone is a hormone with many important functions in the body. So what’s the essence of a hormone?

In ancient Greece, rulers sent out their trusted attendants to deliver messages to other states. They did not have email, Whatsapp, or Skype. Pidgeons weren’t to be trusted. So sending out attendants was the only way to communicate with other states (organs) of the country.

Hormones are like these trusted attendants. When the body has an overall plan, the hormones tell the relevant organs and tissues to perform the related actions.

For example, when your body wants to grow muscle, hormones tell them to shrink or grow. We call these ‘anabolic hormones’. Anabolic means ‘growth-stimulating’. Men and women have different amounts of anabolic hormones. Specifically, men have more testosterone in their systems and women have more estrogen.

This article is about testosterone in men, specifically. (Women; I’m not done with you! Another article will cover estrogen.)

A man can easily change his testosterone hormone levels simply by injecting synthetic testosterone. However, this will wreak havoc on your (hormonal) health. Balls will shrink. Moods will be disturbed. Dependency will develop.

So what can you do to increase testosterone naturally? And is it worth the effort?

In this article I’ll show you how beneficial more testosterone actually is. Next, I’ll uncover some very simple, science-proven ways to boost the amount you have in your body.

I’d rather not talk bullshit. Hover over, or tap on (Tap) to discover the evidence backing the claim.

Jump to section:

• The power of testosterone
• Science-supported ways to increase your testosterone levels naturally
• Testosterone boosting myths
• Conclusion

The power of testosterone

Let’s first look at what more testosterone can do for you. If you inject testosterone from a syringe, miracles happen: you can literally gain pounds of muscle without doing any weightlifting at all (Tap).

However, not everyone is ready to inject synthetic testosterone in their bodies, and wisely so. One thing leads to another… I mean: more types of synthetic hormones.

Anabolic-Androgenic Steroids (AAS) in general – which includes testosterone injections – hold many psychological and physiological dangers, such as:

• Mood swings (anger, irritability, violence) (Tap)
• Impaired sexual functioning (and the impact on your romantic relationship) (Tap)
• Anxiety and paranoia (although using stimulant fat burners play a big role as well) (Tap)
• Heart disease [2] (Tap)
• Psychological dependence (Tap), as in, you cannot stand the sight of not being muscular (Tap)
• Low testosterone, even months after stopping steroids (Tap)

Kelsey 2014 data of normal testosterone values (Tap)

Keep in mind that the type and amount of steroids determine the side-effects. Also, some psychological disturbances related to AAS use are just that: related. It’s not cause and effect. Just like how playing basketball and being tall are related, basketball doesn’t necessarily make you taller.

However, once you start steroids, you basically become addicted to the stuff, and there’s almost no turning back. But let’s leave that for another article.

To summarize: the syringe hurts. In the short and in the long term.

More modest increases in testosterone

It’s clear that injecting testosterone can have dramatic effects on your physique. However, what about more modest testosterone changes within the natural limits?

Even more modest increases [2] of (synthetic) testosterone can significantly grow muscle, as seen in the image.

In men that actually lift weights, these testosterone increases may have even bigger effects.

Take-home messages:

• Testosterone is a very powerful muscle building hormone in men.
• Exogenously injecting testosterone grows pounds of muscle, even without training.
• However, using anabolic steroids holds many dangers, such as psychological addiction and permanent hormonal damage.
• Raising testosterone levels within the healthy boundaries also increases muscle, but to a lesser degree.

However, is there a natural way to increase your testosterone levels by such ~200-400 ng/dL jumps (50 – 150%)?

We’ll find answers in science… These are the methods I’ll cover:

• Eating more dietary fat
• Lowering body fat levels
• Consuming more zinc
• Sleeping more
• Some myths on increasing testosterone

But before we dive into these topics, let me clarify the concepts of “total testosterone” and “free testosterone”. Most of the total testosterone in the blood is bound to Sex Hormone Binding Globulin (SHBG) and Albumin. These can’t easily enter (muscle) cells, especially SHBG-bound testosterone.

What’s left is “free” testosterone, which can easily enter cells and bind to androgen receptors to have its effects. It’s only ~2% of total testosterone in most cases.

Therefore free testosterone is most important, but often a higher total testosterone automatically means more free testosterone, which is why total testosterone can already tell us a lot.

Increasing testosterone levels by consuming more dietary fat

So how can men naturally influence testosterone levels? And by how much?

First of all: by eating differently. Men who consume more dietary fat could potentially see their (free) testosterone increase 10-15% [2, 3], and in general higher fat intakes are related to higher testosterone levels (Tap) .

To give you an idea of how much more fat you should eat: increasing the content of fat in your diet from ~20% of calories from fat to ~40% can accomplish the 10-15% increase.

Extra notes on the studies (Tap).

The unbound free testosterone is actually the active component of total testosterone. It binds to the muscle cell receptors to stimulate muscle growth. Normally it goes up when total testosterone goes up, so total testosterone is a ‘proxy’ for the active free testosterone.

Eating very little fat (under 10% of calorie intake per day) very probably lowers free testosterone levels (Tap).

At the other end of the extreme: what happens if you push the fat content of your diet very high? An unpublished study hints that eating 60% of your calories as fat could further increase your testosterone levels (Tap).

‘

However, these studies did not have the best study designs. The last study I mentioned didn’t even get published in a peer-reviewed scientific journal. So whether or not total testosterone will actually increase is not clearly backed by sound and powerful science.

See study overview sheets.

More importantly, an increase of 10-15% translates to only 50-100 ng/dL, which doesn’t come close to the 200-400 ng/dL jumps we’ve seen are effective to grow pounds of muscle. Let’s look at that figure again.

To demonstrate; these men gained 1.2 kg in 3 months with 63% increase in testosterone (245 to 400 ng/dL), without training. A 10-15% increase in testosterone could theoretically gain them an extra 0.1-0.2 kg of muscle.

Is 100-200 g of muscle mass something you want to critically watch your fat intake for?

So in the grand scheme of things, a 10-15% increase in testosterone probably doesn’t have a big effect on your physique. However, eating more fat is not the only way to potentially increase your testosterone levels…

Take-home messages:

• Clearly, injecting testosterone profoundly increases testosterone levels and muscle gains, even without training.
• It’s unclear whether eating more fat will actually increase (free) testosterone levels in men, although some research shows 10-15% increases.
• Even if testosterone would increase by 10-15%, theoretically this translates to only 100-200 g of extra muscle mass.

Increasing testosterone levels by lowering body fat levels

Men might also increase their testosterone by optimizing their body fat percentage.

Body fat percentage is related to hormone levels. People that are close to ~10% bodyfat tend to have the highest testosterone levels (Tap). However, again; correlation is not causation. No study to date investigated whether lowering body fat levels down to ~10% actually directly enhances testosterone (Tap), although researchers predict that this is the case (Tap).

We do have numbers on what going too low in body fat does to your testosterone. Bodybuilding show contestants saw their testosterone levels decrease by as much as 40% once when they were able to count their ribs (Tap) [2]. However, it’s not certain whether this was due to the low body fat levels, or due to the strong calorie deficit.

You can read more about this in my previous article on the ideal body fat percentage to bulk.

In general I recommend staying between 9 and 13% body fat to ensure optimal testosterone levels from a body fat level perspective.

You can see where you are at with the dropdown figure below.

Take-home messages:

• While body fat levels around 10% are related to optimal testosterone levels, there are no experimental studies to show how much an overweight person’s testosterone increases when he lowers his body fat levels to ~10%. However, this very likely enhances testosterone levels.
• There’s evidence that decreasing body fat to bodybuilding leanness (~6%) decreases (free) testosterone by up to 50%. However, this could also be due to the calorie deficit.

Increasing testosterone levels by consuming more zinc

Let me ask you something:

Do you eat either oysters or 8 oz of red meat every single day?

If not, you may be missing out on extra natural testosterone, as this study clearly shows your testosterone levels are related to the zinc amounts your body carries (Tap). To demonstrate: when some of the study’s participants restricted their zinc intake for 4 months, their testosterone levels plummeted.

After supplementing with zinc, older men with a zinc deficiency saw their testosterone levels rise by 70% in 3 months.

Younger wrestlers and bicyclists that exercised so much that they became zinc deficient also benefited from supplementing zinc: their testosterone levels increased.

Moreover; we know that Egyptian men that suffer from low testosterone also saw their testosterone levels increase after they increased zinc intake.

How much zinc should you consume?

All in all, scientific research hints that zinc deficient men’s testosterone levels could benefit from higher zinc intakes. But how much zinc per day is enough?

Typically, 11 mg of Zinc per day for men and 8 mg for women is advised. However, this is based on older measurement methods that don’t account for decreased zinc absorption. Moreover, intensive exercise – like weight lifting, the stuff we do – also increases zinc needs by about 20%.

Therefore I advise men to consume 20 mg of zinc per day, and women to consume 14 mg.

So how to find out whether you’re zinc deficient? Before your fear of syringes pops in: there’s no blood test to tell this accurately, since your body stores most zinc in actual body cells [2] (Tap).

A better indicator is diet: how much of the stuff are you approximately getting in with your staple foods?

Here’s a list of foods highest in zinc. If you’re not eating any of those regularly, then you may want to start scratching your head.

(see data)

To give you an idea of how likely it is you’re not getting enough: you would need to eat 500 g of red meat, 1.5 gallons (5 Liters) of milk, 40 eggs, or over 2 kg of chicken per day to reach 20 mg zinc (recommended for weightlifting men).

So especially people that don’t eat a lot of animal products are at risk, such as vegans, vegetarians, and flexitarians.

Again, you could increase your testosterone levels by increasing the amount of zinc you consume, but only if you’re deficient in the first place.

I advise this Zinc Picolinate brand if you’re looking for something worthwhile. Every capsule has 50 mg of elemental zinc (the type that matters). However, be mindful not to consume more than 40 mg of elemental zinc per day, as it can induce copper deficiency. This would mean taking the aforementioned capsules every other day. Best is to estimate how much zinc your diet has with the calculator below, and fill the rest with a zinc supplement.

Jump to testosterone potential quiz.

More info on other zinc supplements can be found on my patreon.

Pro-tip: if you’re taking a zinc supplement, try not to take it together with a calcium-rich meal or supplement, since it can seriously affect its absorption (Tap).

Take-home messages:

• Scientific research shows zinc deficiency is strongly related to lowered testosterone levels.
• Since zinc gets stored in your body cells, a blood test cannot accurately assess whether you’re zinc deficient or not.
• If you’re not eating red meat or shellfish daily, there’s a high chance you’re zinc deficient.
• Taking a good zinc supplement can ensure you consume enough zinc, but mind not to over-consume zinc using the calculator above.

Increasing testosterone levels by sleeping more

Finally: sleep. Getting your head on the pillow in time – and keeping it there – can make a significant difference in your testosterone levels.

Two experimental studies showed that restricting sleep to 5 hours or less (compared to over 8 hours) lowered testosterone levels by ~10% (Tap) [2] (Tap). See the image.

Two “observational” studies support the results of these 2 experimental studies: seriously sleep-deprived men (<5 hours sleep per night) generally have up to 50% lower testosterone levels. [1, 2] (Tap) (Tap)

Take-home message:

• While missing an hour of sleep probably doesn’t affect your testosterone much, being seriously sleep deprived (<5 hrs per night) could lower your testosterone levels by 10-50%.

3 debunked testosterone booster myths

There are some things that people think affect their testosterone, but actually don’t. Let’s listen to science.

1. Vitamin D

If you’re a vampire or a world of warcraft addict living in Syberia, then people (including the prestigious Healthline) say there’s a way to increase your testosterone levels: get out more.

Despite what you may have heard, research shows this is simply not true (Tap), even if you’re vitamin D deficient. However, for health and muscle strength it is still a good idea to get enough sun to maintain a light tan ((Tap) [2] (Tap).

If getting out more only exposes you to cold limbs and frozen snot, then – fortunately – there’s also this thing called vitamin D3 supplementation. Taking between 2,000 and 9,000 IUs per day seems the best choice.

2. Ashwagagandha

Ashwagagandha extract from India – also called the ‘horse smell’ herb – is said to increase testosterone levels. Multiple studies support this, but most of their funding comes from supplement companies, such as Arjuna Natural. Therefore we cannot be certain it has such effects, since these companies want to see such outcomes.

3. Soy products

This is a nasty myth that keeps going around. Some men think that because soy products contain estrogen-like compounds (“isoflavones”), eating them will make them start wearing heels and grow breasts. And lower their testosterone levels.

A comprehensive look at the scientific literature tells us the latter is simply not true. A huge meta-analysis of 15 studies shows the isoflavones in soy products don’t significantly affect long term total or free testosterone levels (Tap).

To confirm this, a more recent highly controlled study shows that 200 men who ate an isoflavone-equivalent of 6 oz (150 g) tofu per day did not see any changes in their (free) testosterone levels (Tap).

To highlight a study: for 8 weeks 17 men drank 400 mL extra soy milk per day, which is (also) the isoflavone-equivalent of 150 g (6 oz) tofu. No change in (free) testosterone levels (Tap).

Other studies show even amounts of 350-450 g tofu per day don’t have a meaningful impact on (free) testosterone levels (Tap) [2] (Tap).

Finally, most studies show eating soy products may be good for multiple health outcomes, such as cancer, cardiovascular disease, and metabolic disease (Tap).

Take-home messages:

• We sometimes read vitamin D, Ashwagagandha and soy products may affect a man’s testosterone levels.
• Although vitamin D aids muscle strength and overall health, no science confidently shows it enhances testosterone levels.
• Ashwagagandha to boost your balls? It’s more likely that the supplement companies boosted the test results.
• Eating soy products, even in amounts up to 1 pound per day, does not have a meaningful impact on testosterone levels.

Conclusion

All in all, we can say that yes, we can naturally increase our testosterone levels by:

• Increasing dietary fat intake
• Optimizing body fat levels
• Increasing zinc intake when zinc deprived
• Sleeping more when seriously sleep deprived

Bumping your fat intake up from 20% to about 40% may potentially increase your total testosterone by 10-15%, based on lacking research. However, no well-designed research shows eating more dietary fat increases free testosterone, the “active” portion of total testosterone that actually binds to the androgen receptors.

Reducing your body fat levels to about 9-12% (not any lower) probably optimizes your testosterone levels. Theoretically if you go from 20% to 10% bodyfat, your testosterone may go up by ~15%, but there’s no experimental research to date to confirm this.

Increasing your zinc intake can potentially increase your testosterone levels by up to 70%, but only if you’re zinc deficient in the first place. Especially those who don’t eat a lot of red meat or shellfish are at risk.

Sleeping more when you’re seriously sleep deprived can increase your testosterone levels by 10-15%. However, missing an hour here and there probably doesn’t affect your T much.

The worse your current situation, the more there’s to win

If your fat intake is very low, you can see a beer belly forming, you’re zinc deprived, and when people think the black rings under your eyes are tattoos; then, and only then, you may be meaningfully missing out on testosterone.

By meaningful, I mean that if you would fix all these things, the subsequent rise in testosterone could have a serious impact on your physique. It could add pounds of muscle.

However, if you are a lean, serious trainee who loves eggs and avocados, eats proper amounts of zinc sources, and sleeps well, there’s probably not a lot you can do to naturally increase your testosterone levels in any meaningful way.

The following quiz tells you whether you could substantially increase your testosterone levels.

Testosterone potential quiz