Tongkat Ali – A Herb with Real Potential

So it’s time to remember again: let’s take a close look at what Tongkat Ali, also known as Longjack, can do!

As we always do, today we are calling on science for help.

Tongkat Ali as a testosterone booster

Among the main active ingredients of Tongkat Ali (Eurycoma longifolia), the most important are the quassinoids – these are responsible for the hormonal effects.¹ Quassinoids stimulate the pituitary gland’s production of luteinizing hormone (LH), which in turn stimulates the Leydig cells in the testes to produce testosterone.² LH therefore acts like a kind of “driver” that kick-starts testosterone production.

This mechanism has been demonstrated at the cellular level. But what do clinical trials say?

The highest quality randomized controlled trials (RCTs) – where participants are randomly assigned to either a placebo or active-ingredient group and even the doctor does not know who is in which group – have shown that Tongkat Ali moderately increases testosterone levels, especially in men whose baseline levels were low or whose hormone production had decreased due to stress.^3-7

In the placebo group there were no significant changes, while in those taking Tongkat Ali testosterone levels increased. In some studies, libido, energy levels and muscle mass also improved, but these are subjective measures, so they must be interpreted with caution. No serious side effects were reported, although long-term data are still lacking.

In summary: the effect is of moderate strength, and it does not replace clinical hormone replacement (TRT). However, in the case of an initial decline in testosterone, it may improve the situation and, together with appropriate lifestyle changes, may even help reverse the process.

Tongkat Ali as an anxiolytic

The alkaloids found in the root of Tongkat Ali also have effects on the nervous system. These substances can inhibit the enzyme monoamine oxidase (MAO), which normally breaks down serotonin (the “happiness hormone”), dopamine (key to motivation) and noradrenaline (which regulates alertness and calmness).^8-10

If MAO activity is reduced, these neurotransmitters remain active in the brain for longer. The result may be improved mood, reduced stress and support for emotional balance. Thus, Tongkat Ali acts not only via hormonal pathways, but may also exert mild antidepressant and calming effects.

Besides the evidence at the cellular level, what do clinical studies say?

Several studies have shown that taking Tongkat Ali reduces cortisol levels (the level of the stress hormone).¹¹ This directly contributes to better mood, reduced anxiety and greater psychological stability. In clinical trials, participants reported less fatigue, better overall well-being and reduced anxiety.^12,13 These are also subjective measures, but they still support the relationships observed at the cellular level.

Tongkat Ali as an adaptogen

The two effects discussed above together can contribute to better adaptation to stress. Tongkat Ali on the one hand reduces the levels of stress hormones (e.g. cortisol), and on the other optimizes testosterone levels. As a result, a calmer, yet energized and physically active state develops. This is why the scientific literature often refers to it as an adaptogenic plant.

Tongkat Ali as an immune booster

The other alkaloids of “Longjack” have anti-infective and immune-modulating effects.^14-16

These alkaloids can inhibit cell division in bacteria and parasites. They also influence immune cell signalling pathways, such as the NF-κB and MAPK pathways, which are key players in the inflammatory response.

In cell-level studies, Tongkat Ali alkaloids induce apoptosis (programmed cell death) in certain tumour cells.

These active compounds’ immune and anti-infective effects are mainly documented at the level of laboratory (in vitro, cell culture) and animal experiments, while human clinical trials are still very limited.

Comparison with other testosterone boosters

So Tongkat Ali has clinically proven testosterone-boosting properties, but it cannot further increase an already normalized testosterone level.

It is particularly beneficial for men living under high physical and mental stress and for men as they get older.

Ashwagandha has also been shown to increase testosterone levels, but this herb acts more indirectly – via optimization of stress hormones. Therefore, it can be a good complement to Tongkat Ali, but it does not match it in terms of its effects on libido and male vitality. While Tongkat Ali is specifically recommended for men, ashwagandha’s general health-promoting effects make it a good choice for both sexes.¹⁷

Tribulus terrestris is widely used, but most clinical studies have not shown a significant testosterone-boosting effect. It has proved to be more effective in improving libido and erection.¹⁸ This observation highlights that male “performance” is not solely dependent on testosterone. Tribulus increases nitrogen oxide production in endothelial cells, improving blood flow in the penis and resulting in stronger erections – all while leaving testosterone levels almost unchanged or increasing them only very slightly.

Panax ginseng is primarily known for its libido-enhancing effect, but some studies have also shown a mild increase in testosterone levels. In addition, it improves general vitality and male reproductive function.¹⁹

Fenugreek is one of the few plants that has shown effects similar to Tongkat Ali. In clinical studies it significantly increased free testosterone levels and improved strength and endurance.²⁰

Can women take Tongkat Ali?

Interestingly, the effects of Tongkat Ali have recently begun to be investigated in peri- and postmenopausal women as well. According to the data so far, there is a noticeable reduction in stress and an increase in vitality, but no testosterone rise of the same magnitude has been documented as in men. Furthermore, no serious side effects have been reported.²¹

This immediately raises the question: why is the effect different in women?

As we discussed at the beginning of the article, Tongkat Ali exerts its effect through activation of luteinizing hormone (LH). In women it also activates this hormone, but its role is different there. In the ovaries, LH does not primarily regulate testosterone production, but rather ovulation and the cyclic regulation of progesterone/oestrogen (the female sex hormones).

In women, testosterone production occurs in smaller amounts (mainly in the ovaries and adrenal cortex), so increasing LH does not lead to a significant rise in testosterone.

Therefore, in women the effect of Tongkat Ali is manifested more in stress reduction, vitality and mood improvement, rather than in the classic hormone-enhancing sense.

Since its effects in women are even less studied, taking it may require consultation with a specialist.

Recommended dose of Tongkat Ali

The usual dose of Tongkat Ali (standardized, water-soluble extract) is 100–600 mg per day.²²

At such doses its use is considered safe, and only minor side effects may occur, such as^22,23:

• Insomnia, restlessness, irritability: due to its stimulating effect, some people may experience sleep disturbances.
• Nausea, stomach upset: this may rarely occur, especially at higher doses.
• Changes in blood pressure and heart rate: although rare, its stimulating effect may cause such changes in sensitive individuals.

No serious side effects have been documented, but long-term data are still incomplete.

Is Tongkat Ali safe?

Longjack shows mild side effects and is generally considered safe. However, there are situations/conditions where its use requires caution or medical consultation.

Quality concerns – these do not stem from the herb itself, but from manufacturing conditions:

• Some studies have found lead and mercury contamination in certain Malaysian products.
• There have been cases where products contained undeclared sildenafil analogues (compounds similar to drugs used for erectile dysfunction).

The safest option is to choose a product from a reliable source – a manufacturer that has GMP certification and backs its products with independent laboratory testing.

Possible side effects of Tongkat Ali

• According to clinical studies, it is generally well tolerated, and only mild digestive complaints (abdominal pain, dyspepsia, constipation) have been reported.²²
• In a single documented case: acute liver injury occurred in a 47-year-old man who experienced nausea, vomiting, elevated liver enzymes and jaundice after taking it. – So always choose a reliable, laboratory-tested product, and if someone has liver disease or is taking medication, medical consultation is recommended.

Drug interactions and conditions in which it should be avoided:

• Pregnancy and breastfeeding: safety has not been established, so it should be avoided.
• Antidepressants: Tongkat Ali alkaloids affect monoamine oxidase, just as many antidepressants act along this pathway. Due to this shared mechanism, consultation with the treating physician is necessary.
• Hormone-dependent cancers (e.g. prostate, breast cancer): due to its testosterone-modulating mechanism, it should be avoided.
• Psychiatric disorders (anxiety, bipolar disorder): in some cases Tongkat Ali may worsen symptoms.²⁴
• High blood pressure: according to some studies, Tongkat Ali may have a blood-pressure-lowering effect. At the same time, due to its influence on testosterone, it could theoretically also increase blood pressure, since enhanced hormonal activity may stimulate the circulation. For safety, consultation with the treating physician is recommended.

Which product should I choose?

The Double Wood Supplements Tongkat Ali Extract contains 500 mg of extract per capsule. It has GMP certification and its quality is guaranteed by an independent laboratory.

The Nutricost Tongkat Ali – Vegan: also contains 500 mg of extract per capsule. The “pinch” of black pepper extract ensures optimal absorption. The product is manufactured in an NSF* certified, GMP-compliant, FDA-registered facility. *Quick note: NSF certification is an independent quality assurance system which, in the case of dietary supplements and vitamins, confirms that the product really contains what is stated on the label and does not contain harmful contaminants.

The Oly Tongkat Ali: likewise contains 500 mg of extract per capsule and is tested by a third party.

Vitamin360’s choice would be Nutricost Tongkat Ali. For two reasons:

• This manufacturer has the most certifications.
• The extra black pepper extract slightly improves absorption.