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Prolactin and Testosterone Relationship

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Prolactin and testosterone both play a role in male health, and whilst some hormones work together to improve well-being, some have a negative impact on each other

This article looks at the two in detail, introducing you to the role that it plays within the body, but also how it affects your T levels.

In this article you will learn:

  • What is prolactin?
  • The prolactin – testosterone relationship
  • What you can do to lower your PRL levels
  • Summary – does it lower testosterone?


What is prolactin?

Prolactin (PRL), Also known as ‘luteotropic hormone’ or luteotropin’ is a hormone that is produced in an area of the brain called the pituitary gland by specific cells called lactotrophs.

PRL is often informally referred to as the ‘milk hormone’ due to its function and ability to produce breast milk in females (‘lactation’). In reality though it has hundreds of other functions that control metabolic and immune functions too – for example it is a key regulator in reproduction and male health. 

Levels of this hormone fluctuate throughout the day – this is referred to as a circadian rhythm. Typically, PRL levels are highest during sleep but are also elevated during times of emotional or physical stress such as during high-intensity exercise. For females, as you would expect, levels are elevated after childbirth so as to help produce milk for feeding.

Although PRL levels are controlled and regulated by many different hormones,  there are two key hormones you need to know about here:

  • Dopamine – this hormone is released from the hypothalamus – an area of the brain just above the pituitary gland. It puts the brakes on PRL production so the more dopamine there is, the less PRL is produced. Dopamine and testosterone share a common pattern – if this hormone increases, T does too.
  • Estrogen – This hormone increases production of PRL, and is particularly important for women after labor as you can imagine. Estrogen also puts the brakes on T production.

Although there are a number of other hormones involved in this ‘negative loop’ process, try to see dopamine as the ‘gas’ behind T production, and estrogen a the ‘brake’.



Key Point: Prolactin has a number of different function that help to regulate metabolism, reproduction and your immune system

The prolactin and testosterone relationship

Testosterone and dopamine are somewhat friendly towards each other – if dopamine is elevated, T generally follows suit. However, Testosterone works antagonistically with estrogen and PRL– if these are elevated then T levels decrease.

PRL inhibits the release of a hormone called gonadotropin-releasing hormone (GnRH) which is released from the hypothalamus. This hormone directly stimulates the Leydig cells of the testes to produce testosterone. So if GnRH is inhibited by PRL, testosterone will suffer.

High prolactin levels have been found to lower testosterone levels – and this can cause a drop in your libido as well as symptoms of erectile dysfunction. It can also cause gynecomastia – an increase in breast-like tissue. If you think that the female hormone estrogen stimulates PRL, then ‘man breasts’ makes sense as a consequence.

Men with erectile dysfunction who are found to have a low testosterone level should be aware of their PRL level [1]

Too much PRL, a condition known as hyperprolactinaemia, could be caused by a number of different things – medications that reduce dopamine, thyroid dysfunction, and also tumors on the pituitary gland – referred to as ‘prolactinomas’. Regardless of the cause, high PRL can cause testosterone deficiency, loss of muscle mass, and decreased body hair so it is important that you effectively manage your levels so that you don’t suffer any long-term side effects.

There are a number of other symptoms and side effects of elevated PRL. Here are just a few:
– Anorgasmia – absent or delayed ejaculation
– Sensitive nipples that may discharge fluids
– Fatigue, tiredness and lethargy
– Mood swings, low mood and depression


Key Point: Prolactin has been found to decrease testosterone levels and contribute to a number of side effects including loss of libido, erectile dysfunction and mood swings.

What can you do to lower your prolactin levels?

1.Supplement with vitamin B6

Studies have found that by supplementing a single 300mg dose of pyridoxine –  vitamin B6, not only will you boost testosterone, you will also decrease your PRL levels [2].

A study in the New England Journal of Medicine found that when 600mg of B6 was supplemented during intense exercise, not only was PRL completely diminished, but growth hormone was elevated in the 1 hour post-workout period too [3].

Regular supplementation of the vitamin not only supports your hormones, it also helps to boost your T levels and improve overall health of the eyes, hair, skin and liver.

2.Sleep regularly

Good quality, regular sleep is important for energy levels, repair, recovery, and mental well-being. Sleep is also very effective at reducing cortisol levels – your body’s stress hormone, and elevating testosterone. It has been found to reduce estrogen, elevate dopamine and of course lower your PRL levels, so make sure you don’t skip on it.

3. Zinc

Zinc supplementation has been found to inhibit PRL levels in both men and women. A study in Hormone and metabolic research found that by supplementing 50mg of zinc, levels fell below baseline within 2 hours [4]. As zinc has also been found to elevate T levels, this is a mineral you really should consider using on a regular basis.

4. Avoid anabolic steroids

Steroids such as Trembolone and Nandrolone have been found to elevate PRL and should be avoided. These androgenic-anabolic steroids belong to the 19-nor testosterone family and as such are recognized by the body as a progestin – these synthetic progestogens have the ability to increase PRL levels.

Summary – does prolactin decrease testosterone?

Prolactin is a hormone produced by the pituitary gland that regulates a number of metabolic, reproductive and immune functions. It is controlled by a number of other hormones but inhibited mainly by dopamine – if dopamine is low, then prolactin becomes high – this can have a negative effect on T levels.

The release of excess PRL has been found to decrease testosterone as it inhibits the release of a hormone called gonadotropin-releasing hormone which acts to stimulate the testes. As a result, a number of side effects may occur; these include:

a) Reduced libido

b) Mood swings and depression

c) Loss of muscle mass

d) Erectile dysfunction

e) gynecomastia

There are a number of measures that you can take to reduce prolactin levels and keep testosterone elevated; these include getting good quality, regular sleep; the avoidance of anabolic steroids and the inclusion of supplements such as zinc and vitamin B6.

Where’s a good place to start?

In order to get the best quality zinc and vitamin B6, as well a host of other testosterone boosting ingredients you need to go with a high-quality supplement. TestoFuel is a top-of-its-game complex containing only the best, most scientifically tested compounds.

As a premium, T booster, TestoFuel supplies your body with essential nutrients needed to optimize your testosterone levels:

  • Muscle Growth and Strength – Bigger size and stronger lifts
  • Improved Recovery – Faster growth and less soreness
  • Enhanced Enhanced Energy – More motivation to train stronger for longer
  • Healthy Libido – Ramp up sex drive and improve confidence

TestoFuel is ideal for improving your performance both in and out of the gym, and helping you attain that all-important muscular physique.


  1. Zeitlin, SI. Hyperprolactinemia and Erectile Dysfunction. Rev Urol. 2000 Winter; 2(1): 39–42.
  2. Delitala, G et al. Effect of pyridoxine on human hypophyseal trophic hormone release: a possible stimulation of hypothalamic dopaminergic pathway. The Journal of Clinical Endocrinology & Metabolism. 2009; 42(3)
  3. Moretti, C et al. Pyridoxine (B6) Suppresses The Rise In Prolactin And Increases The Rise In Growth Hormone Induced By Exercise. N Engl J Med. 1982; 307(7): 444-5.
  4. Brandão, NJ et al. Zinc: an inhibitor of prolactin (PRL) secretion in humans. Horm Metab Res. 1989; 21(4): 203-6