keto lowers testosterone

Does Keto raise Testosterone?

What is Keto?

Keto is a diet model, where only 5-10% of your daily caloric intake is made up of carbohydrates. It has been around for some years and it has some main benefits:

Benefits of Keto

  • Supports weight loss.
  • Stable energy levels through the day.
  • Improves acne.
  • Stable blood glucose

Keto has some drawback though, drawbacks that are not often talked about, mainly related to testosterone:

Keto effects on Testosterone

Keto (and low carb diets in general) are bad for your testosterone. Simple as that. They lower your testosterone in 4 different ways :


  • Higher SHBG (Sex Hormone Binding Globulin)
  • Lowers T3 (Thyroid Hormone)
  • Lowers GnRH (Gonadotropin-Releasing Hormone)
  • Increases Cortisol (Stress Hormone)


We will explore how these factors influence T & how to utilize carbs to get higher T.

Keto, Testosterone and Cortisol

Cortisol is the stress hormone. It is the hormone that turns your immune system on and it also directly downregulates testosterone production.


When on low carb, (calories from carbs<35%), resting + post workout levels of cortisol upregulate. After the first 3 weeks, only post workout levels of cortisol are upregulated.


Even after the first 3 weeks (commonly called keto flue), resting testosterone levels go down by ~150ng/dl (~5.2nmol/L).

Effects of Keto on GnRH

Gonadotropin-Releasing Hormone. It is responsible for stimulating the pituitary gland to release luteinizing hormone, which in turn stimulates your balls to create testosterone.


GnRH release is done in pulses, the pulses are controlled by your glucose levels. Sustained low glucose levels decrease the total release of GnRH, leading to your balls not working at 100% of their capacity, leading to less testosterone production.

Keto and the Thyroid

T3 plays a huge role in your metabolic rate. A low level of T3 (hypothyroidism) leads to low body temperature, low metabolic rate, low brown fat activation, putting on fat easily.


Studies have found that a low carb intake decreases T3 levels by ~50ng/dl (normal range 60-180 ng dl), which makes the decrease extremely significant.


You want high normal levels of T3 for optimal metabolism health + great energy levels during the day.

Testosterone and SHBG

Sex Hormone Binding Globulin binds free testosterone.


Free testosterone is the only kind of testosterone utilized by your body. When free testosterone is binded by SHBG, it becomes unusable.


Keto, and low carb in general, increases SHBG levels, leading to less free testosterone available in your body.

How much carbs to eat for testosterone

You should get at least 45% of your daily calories from carbs to avoid the negative effects of low carb. This does not mean you should eat garbage though.


Processed carbs are to be avoided under all circumstances, and grains, even though they are a more nuanced topic, in general should be avoided too (grains : corn, wheat, etc).


What you should consume is starches (potatoes, yams, carrots, etc), and all kinds of fruits. With fruits though, be careful, juices do not count and are TRASH.


Avoid extreme diets. Cutting out carbs completely impacts your testosterone and general health negatively. Stick to complex carbs + starches, avoid grains and processed carbs.

For more information on testosterone and looks, click here.

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