Introduction

Tongkat ali, also known as Longjack, is a traditional herbal remedy taken for low testosterone, poor libido, male infertility and erectile dysfunction. It is derived from the roots of the Eurycoma longifolia plant. This plant is native to Southeast Asia and grows in Malaysia, Indonesia, and Thailand.¹ It is available commercially in capsule and powder form. In this article, we will look into the potential use of tongkat ali in boosting testosterone levels and the risks associated with its use.

Understanding testosterone

Testosterone is an essential sex hormone in both men and women. Testosterone plays a vital role in maintaining muscle mass, bone density, and sexual function. In men, testosterone is essential for sperm production, muscle growth, and maintaining libido, whilst in females, it supports bone health and sexual well-being.²

Testosterone hormone levels decline naturally with age, but other factors, such as poor diet, lack of exercise, and certain medical conditions, can also negatively impact hormone levels.

Poor diet

• A diet lacking essential nutrients can impair testosterone production. For example, zinc and vitamin D are crucial for maintaining healthy testosterone levels 
• Consuming excessive amounts of sugars in the diet can lead to insulin resistance, which is associated with lower testosterone levels
• Research also shows that diets high in processed foods and unhealthy fats can lead to inflammation and oxidative stress, negatively affecting testosterone production³ 

Lack of exercise

• Sedentary lifestyles contribute to weight gain and obesity. Excess body fat, especially around the abdomen, is linked to lower testosterone levels. Fat cells convert testosterone to oestrogen, decreasing the amount of testosterone available for the body
• Additionally, lack of exercise can lead to muscle loss, which negatively impacts hormone levels⁴
• When we exercise, we boost the levels of hormones called endorphins. These hormones reduce stress and promote better sleep, both of which are important for maintaining healthy testosterone levels; conversely, a lack of exercise can lead to increased stress and poor sleep, negatively impacting testosterone levels⁵

Medical conditions associated with low testosterone levels 

• Type 2 diabetes is often associated with low testosterone levels. Insulin resistance, a hallmark of diabetes, can interfere with the hormone’s production⁶
• Conditions such as kidney disease, liver disease, and chronic obstructive pulmonary disease (COPD) can negatively impact overall health and testosterone levels^7,8,9
• Hypogonadism – a condition where the body doesn’t produce enough testosterone due to problems in the testes or pituitary gland¹⁰ 
• Poor sleep quality and disorders like sleep apnoea can reduce the amount of deep sleep, which is crucial for testosterone production. Testosterone levels typically peak during sleep, and disruptions can significantly lower hormone levels¹¹ 

How might tongkat ali help with low testosterone and how does it do it?

Many studies conclude that supplementing with tongkat ali in men with low testosterone, who are otherwise healthy, may improve their erectile function, increase their fertility, and enhance their sexual function and overall well-being.^12,13,14 

Researchers haven't studied in detail how tongkat ali increases testosterone. However, this effect most probably occurs through two main pathways: 

1. Tongkat ali contains a bioactive molecule called eurycomanone. Eurycomanone enhances the production of precursors to testosterone production, such as pregnenolone and DHEA. Eurycomanone also inhibits the enzyme (aromatase) that converts testosterone into the female sex hormone, oestrogen^15,16
   
2. Eurycomanone also increases the production of luteinising hormone (LH) and follicle-stimulating hormone (FSH). LH acts upon cells in the testes known as Leydig cells, causing them to release testosterone, while FSH increases sperm production^17,18 

How effective is tongkat ali?

A systematic review and meta-analysis in 2022 examined nine studies on the effects of tongkat ali on testosterone levels. In these studies, 100 to 600 mg was used daily for periods between 2 weeks and 12 weeks, with one study lasting six months.

The studies showed a significant increase in testosterone levels for those taking tongkat ali compared to a placebo. This increase was considered significant.

The benefits of tongkat ali were more apparent in men with low testosterone levels (below 300 ng/dL), who saw a significant increase. In contrast, men with normal levels (above 300 ng/dL) did not see a significant change.

In summary, whilst those with low testosterone levels may experience a boost from taking tongkat ali, it seems that those who have normal levels, to begin with, may not see a significant improvement.¹²

Does tongkat ali have any other benefits?

Tongkat ali has mainly been studied for its use as an aphrodisiac. However, the mechanisms by which tongkat ali may enhance sexual function still need to be better understood, and most of the research has not been conducted on humans.¹⁶ This effect is based on lore and tradition rather than hard evidence. It has also been traditionally used as an antimicrobial, antimalarial and anti-cancer agent.¹⁶

Antioxidant 

Tongkat Ali contains alkaloids, flavonoids and superoxide dismutase (SOD), amongst other compounds which are antioxidants, meaning they neutralise free radicals in our body. This protects us from oxidative stress, which harms our cells and contributes to certain diseases and ageing. It is important to note that antioxidants perform many other useful functions in our body.¹ 

Osteoporosis prevention 

Interestingly, antioxidants also prevent bone loss and help retain bone mass, as oxidative stress is involved in osteoporosis. Tongkat ali stimulates the destruction of bone cells which break down bone (osteoclasts) and aids the formation of cells which form new bone tissue (osteoblasts). Since our ability to combat oxidative stress declines with age, getting plenty of antioxidants will help prevent fractures and keeping your bones strong.¹

Stress-reduction

One human study found evidence of an anxiolytic (anxiety and stress-reducing) effect of tongkat ali. Lower cortisol levels and improved mood parameters were reported upon tongkat ali consumption. However, it should be noted that human evidence for these anxiolytic outcomes is somewhat limited, given the lack of published randomised controlled trials in humans. More research is thus needed to validate these findings.¹⁹

Are there any negative effects of taking tongkat ali?

The safety and quality of tongkat ali (Longjack) supplements need to be better studied in humans, and there needs to be more standardised regulations for their commercial production. 

• Some studies have found that tongkat ali supplements can be contaminated with heavy metals like lead and mercury, particularly those originating from Malaysia. These levels can exceed safe limits, posing health risks²⁰ 
• Studies in humans have shown that taking tongkat ali in doses between 200 and 600 mg per day generally causes only minor side effects such as stomach discomfort and itching. Serious side effects are rare²² 
• Tongkat ali can interfere with propranolol, a common medication taken for high blood pressure and anxiety, reducing its effectiveness. People taking propranolol, or any other medication, should talk to their doctor before using tongkat ali²³ 

Who should avoid taking tongkat ali?

Tongkat ali is generally considered safe when taken in the recommended doses. However, there is very limited research on possible side effects or contraindications to its use.²⁴ Generally, it would not be recommended for:

• Pregnant and breastfeeding women
• Men with breast or prostate cancer
• People with diabetes, heart disease, kidney disease, liver disease, or sleep apnoea
• Children

Summary

In summary, tongkat ali shows potential as a natural supplement for boosting testosterone, particularly in men with low levels of this hormone. The herb may also offer additional benefits such as improved libido, enhanced fertility, and reduced stress. However the safety and quality of commercial tongkat ali supplements can vary and there have previously been concerns about supplements being unregulated or contaminated. 

Before starting any new supplement, including tongkat ali, it is crucial to consult with a medical professional to ensure it is safe for you to take. Moreover, supplements should not be used as a replacement for a healthy diet and lifestyle.