FAQ: Warnings and Side Effects of Tongkat Ali [Part 1]

When researching Tongkat Ali, many people have questions about its effectiveness, safety, and proper usage.

Common concerns include whether Tongkat Ali truly boosts testosterone and vitality, what the right dosage is, and whether long-term use may affect the liver or kidneys.

In addition, side effects and drug interactions are among the most searched topics. In this article, we’ll address the most frequently asked questions to help you better understand Tongkat Ali’s benefits, potential risks, and how to use it safely and effectively.

Special Populations and Underlying Health Conditions

1. Can Diabetics Take Tongkat Ali?

They can, but with caution. Several preclinical studies (on mice) suggest Tongkat Ali has blood sugar–lowering effects — somewhat like a diabetes drug. In diabetic mice, Tongkat Ali root powder significantly reduced blood glucose and HbA1c levels and increased insulin secretion [1].

However, human data are still limited. Experts advise those taking antidiabetic medications to consult a doctor before using Tongkat Ali, as it may enhance the effects of these drugs and cause hypoglycemia [2, 3].

In summary, people with diabetes may use Tongkat Ali, but only at low doses, under strict medical supervision, and with regular blood glucose monitoring.

2. How to Take Tongkat Ali if You’re a Diabetic?

There are no official guidelines yet. If approved by your doctor, start with a low dose (e.g., 200–400 mg/day) divided into two doses after meals to minimize the risk of hypoglycemia. Always monitor blood glucose before and after taking it during the first few days.

Report any signs of low blood sugar (dizziness, sweating, tremors, rapid heartbeat) to your doctor.

Most importantly, stay in close contact with your healthcare provider: if your glucose drops too low, your medication dose may need adjustment. In general, Tongkat Ali use should be “carefully titrated and monitored” for people with diabetes [2].

3. Is Tongkat Ali Safe for Diabetics?

In theory, Tongkat Ali may be safe — and even beneficial — for people with mild type 2 diabetes or prediabetes since it appears to enhance insulin secretion and sensitivity [1].

However, because of its glucose-lowering effect, safety depends on medical monitoring and drug adjustments. Some references even list it as contraindicated in diabetes due to this effect [3].

Therefore, there is no definitive conclusion about its complete safety. If you have diabetes, it’s best to consult an endocrinologist, monitor your blood sugar regularly, and be ready to adjust your treatment plan as needed.

4. Is Tongkat Ali Good for High Blood Pressure?

There are no clear human studies showing that Tongkat Ali helps manage hypertension. In contrast, some animal research suggests it may lower blood pressure in hypertensive models.

For example, a study on high-fat diet–induced hypertensive rats found that Tongkat Ali reduced both systolic and diastolic blood pressure, possibly through increased testosterone and vasodilation [4].

For healthy individuals, there’s no evidence that Tongkat Ali raises blood pressure. Therefore, if it has any effect, it may slightly lower rather than raise blood pressure. However, these effects in humans remain unconfirmed and may vary among individuals.

5. Can a Man with High Blood Pressure Take Tongkat Ali?

Men with hypertension are not strictly prohibited from using Tongkat Ali, but medical approval and monitoring are recommended.

RxList lists “heart disease” as a contraindication for Tongkat Ali [3]. Still, if you only have uncomplicated high blood pressure (without major cardiovascular disease), using Tongkat Ali is generally not considered absolutely forbidden.

Since Tongkat Ali may lower blood pressure in some cases [4], men with stable hypertension may take it under a doctor’s supervision.

If you’re on blood pressure medication, monitor your BP regularly, as Tongkat Ali could have an additive effect and cause hypotension.

6. Can You Take Tongkat Ali with Blood Pressure Medicine?

No specific studies have examined interactions between Tongkat Ali and antihypertensive drugs.

However, since Tongkat Ali might mildly lower blood pressure, combining it with antihypertensive medications (e.g., ACE inhibitors, vasodilators, etc.) could amplify the effect.

Therefore, if you are currently taking BP medication, inform your doctor before adding Tongkat Ali. The general rule is: never combine supplements with prescription drugs without medical advice. Your doctor can decide whether medication adjustments are necessary.

7. Is Tongkat Ali Contraindicated for High Blood Pressure?

In theory, simple hypertension is not listed as an absolute contraindication for Tongkat Ali. However, most herbal safety guides include “cardiovascular disease” (which may cover severe hypertension) as a general contraindication [3].

This means that if you have heart disease or hypertension with cardiac complications (such as heart failure or a history of heart attack), you should avoid Tongkat Ali.

For mild to moderate hypertension without heart disease, some experts believe it can be used cautiously under medical supervision. Overall, mild hypertension should not automatically be considered an absolute contraindication — but always consult your doctor.

8. Does Tongkat Ali Raise Blood Pressure?

No evidence suggests that Tongkat Ali increases blood pressure. In fact, animal studies indicate it may lower blood pressure in hypertensive subjects [4]. In healthy individuals, blood pressure does not appear to be significantly affected.

Therefore, if you are healthy, Tongkat Ali is unlikely to raise your blood pressure; if you have hypertension, it may even slightly reduce it. Still, more human research is needed to confirm this effect.

9. Does Tongkat Ali Thin Blood?

Current human studies do not show that Tongkat Ali affects blood thickness or clotting function. No serious side effects have been reported in humans. In a 2-month study of 20 healthy men taking 600 mg daily, no adverse changes in blood, liver, or kidney markers were observed [11].

However, some chemical compounds in Tongkat Ali have shown anticoagulant activity in animal models [5], implying it may increase bleeding risk similarly to blood-thinning drugs.

Therefore, if you’re taking anticoagulants (such as warfarin, high-dose aspirin, etc.) or have a bleeding disorder, you should be cautious.

Generally, Tongkat Ali may have mild “blood-thinning” effects, so avoid combining it with anticoagulant drugs unless under medical supervision.

10. Is Tongkat Ali Bad for Kidneys?

Currently, no human studies show Tongkat Ali harms the kidneys. On the contrary, some animal studies (in models of high uric acid–induced kidney damage) suggest it may protect renal health — reducing creatinine and urea levels and improving kidney tissue structure (Wang et al., 2023).

However, long-term human data are lacking. Therefore, if you already have kidney disease (such as chronic kidney failure or nephritis), consult your doctor before use.

Overall, Tongkat Ali is not considered “harmful” to the kidneys at standard doses, but caution is advised if you have preexisting kidney issues, as any herb or supplement can accumulate in the kidneys over time.

11. Can Tongkat Ali Cause Liver Damage?

In short-term human studies on healthy participants, Tongkat Ali has not been shown to increase liver enzymes.

Specifically, LiverTox (a clinical toxicology reference by the U.S. National Institutes of Health) notes that in short-term clinical trials, “adverse events were few, unrelated to treatment, and did not alter serum ALT, AST, or bilirubin levels” [5].

However, a few rare case reports of liver injury (hepatitis) have been associated with Tongkat Ali use, usually among individuals who were also taking anabolic steroids (e.g., bodybuilders).

In such cases, it was unclear whether the liver injury was caused by Tongkat Ali or by illicit steroid use.

In summary, if you have chronic liver disease (such as cirrhosis or hepatitis), you should avoid Tongkat Ali. For healthy individuals, the risk of liver damage from Tongkat Ali is very low but not zero [5].

12. Can Tongkat Ali Cause Cancer?

There is no evidence that Tongkat Ali causes cancer in humans. The main active compound, eurycomanone, in Tongkat Ali has also been shown to inhibit cancer cell growth and promote cancer cell death in both in vitro and in vivo studies (Jothi et al., 2023).

That said, the European Food Safety Authority (EFSA) has warned that very high doses (around 2,000 mg/kg in rats) could cause DNA damage in the stomach and intestines. This suggests potential genotoxicity, but not necessarily carcinogenicity in humans at normal doses.

To date, no clinical or epidemiological reports have linked Tongkat Ali to increased cancer risk. In summary, Tongkat Ali is not considered carcinogenic, and some preclinical research even indicates possible anticancer properties [2].

13. Is Tongkat Ali Safe to Take After a Mild Traumatic Brain Injury (MTBI)?

Unfortunately, there are no specific studies evaluating the safety of Tongkat Ali use after mild traumatic brain injury (MTBI). Tongkat Ali is not a central nervous system drug — its main known actions involve hormonal regulation and stress reduction [2]. Therefore, it is not used to manage MTBI.

If you have recently experienced MTBI, it is crucial to follow your physician’s recovery plan (rest, neurological rehabilitation, etc.).

If you are considering Tongkat Ali for general well-being — such as to reduce stress or improve testosterone levels — you should consult your neurologist or managing physician first.

Currently, there is no evidence that Tongkat Ali negatively affects MTBI recovery, but there is also insufficient data to confirm that it is completely safe.

14. Can Tongkat Ali Interfere with Antidepressants?

No published studies or case reports have documented direct interactions between Tongkat Ali and antidepressant medications (such as SSRIs, SNRIs, or MAOIs).

Tongkat Ali does not act on serotonin or norepinephrine pathways, unlike antidepressants. Instead, it is known for its ability to reduce cortisol and improve mood modestly [2].

Some studies show that Tongkat Ali may reduce stress and emotional tension (less anger and irritability) in users [2]. Theoretically, this means it has a low likelihood of pharmacological interaction with SSRIs.

However, because individual responses vary, it is always best to consult a doctor before combining Tongkat Ali with prescription medications. Also, because Tongkat Ali can mildly influence mood (for example, increasing alertness or motivation), monitoring for psychological effects is recommended.

15. Can I Take Tongkat Ali with Antibiotics?

Yes, it generally can. In fact, Tongkat Ali itself has demonstrated antibacterial and antiparasitic activity in multiple scientific studies [7]. A systematic review concluded that Tongkat Ali has “potential as an antimicrobial and antiparasitic agent,” consistent with its traditional use for helping fever and jaundice [7].

This suggests that taking Tongkat Ali alongside antibiotics is unlikely to reduce antibiotic effectiveness, and the two might even have complementary actions (though clinical confirmation is lacking).

In summary, there are no known harmful interactions between Tongkat Ali and antibiotics. Nonetheless, always follow your antibiotic prescription exactly and consult your doctor before adding any herbal supplement.

16. Does Tongkat Ali Interact with Medications?

In summary, information on Tongkat Ali’s drug interactions remains limited. No serious interactions have been confirmed, but it lists up to 26 medications that could potentially interact with Tongkat Ali [3].

Notably, Tongkat Ali may enhance the effects of blood sugar–lowering drugs [2, 3] and may amplify blood pressure–lowering effects when combined with antihypertensives. Other herbal compounds — such as rhubarb and roselle (Hibiscus sabdariffa) — are also listed as having moderate interactions with Tongkat Ali [3].

Therefore, as a general rule, always inform your doctor or pharmacist about all medications you are taking — including prescription drugs, over-the-counter medicines, and dietary supplements.

17. Does Using Tongkat Ali While on Medications Like Accutane Pose Any Risks?

No specific studies have examined the concurrent use of Tongkat Ali and Accutane (isotretinoin), a prescription medication for severe acne. Therefore, there is no established data confirming either the safety or risk of this combination.

However, it’s important to note that Accutane can have serious side effects — including those affecting the liver, skin, and mood — and Tongkat Ali also occasionally influences liver function and hormone levels.

For this reason, if you are taking Accutane, do not start Tongkat Ali without consulting your dermatologist or physician. They can assess your condition and monitor liver function and other parameters if supplementation is considered appropriate.

Digestive Issues and Allergic Reactions

1. Can Tongkat Ali Cause Constipation?

According to LiverTox (NCBI, NIH) — a toxicology database — constipation is not listed as a side effect of Tongkat Ali at normal dosages. Reported digestive reactions include nausea, abdominal discomfort, diarrhea, and rash [5].

In the review “Review on a Traditional Herbal Medicine, Eurycoma longifolia” (Rehman et al., 2016), the authors mention “constipation” as one of the traditional uses of the plant in folk medicine, but there is no clinical evidence confirming that Tongkat Ali causes constipation in humans [8].

Therefore, the likelihood of Tongkat Ali causing constipation is very low or unreported in modern medical studies.

2. Can Tongkat Ali Cause Diarrhea?

Yes. LiverTox notes that at typical doses, digestive side effects may include mild diarrhea or loose stools [5].

On Reddit, one user shared that after 17 days of taking 2% Tongkat Ali, starting with 200 mg each morning and increasing to 400 mg, he experienced nausea, dizziness, mild diarrhea, and insomnia (which improved but returned when the dose increased).*

His libido also increased noticeably. He was also taking phenylpiracetam 100 mg, which may have contributed to these effects.*

This suggests that Tongkat Ali may cause mild diarrhea, especially when starting or increasing the dose, but it is generally not severe.

3. Can Tongkat Ali Cause Stomach Problems?

It may cause mild stomach irritation, such as abdominal pain, discomfort, or cramps — especially when taken on an empty stomach or when the product is of poor purity. LiverTox lists “abdominal discomfort” as a possible side effect [5].

In “Safety of Eurycoma longifolia root extract” (EFSA, 2021), although the study focused on allergenic risks, the authors warned that the protein content (up to ~45%) in the extract could trigger unwanted reactions, including digestive discomfort, in sensitive individuals [9].

4. Can Tongkat Ali Make You Nauseous?

Yes. LiverTox notes that nausea is a dose-dependent side effect that some users may experience [5].

On Reddit, one user shared that after five days of taking 2% Tongkat Ali together with Primavie Shilajit, they experienced nausea and vomiting about 20 minutes after ingestion, even though Shilajit alone had never caused issues before.*

Despite this, they reported feeling more energetic and rejuvenated, saying it made them feel a few years younger.*

5. Can Tongkat Ali Cause Nausea, Vomiting, or Stomach Issues Like Gastroparesis?

Tongkat Ali may cause mild nausea or vomiting in some cases, but there is no evidence suggesting it causes gastroparesis (delayed stomach emptying).

Nausea has been reported (as noted above). Vomiting is rarely mentioned in major medical databases, but LiverTox refers to “nausea” and “abdominal discomfort” — including one case report of a man who experienced vomiting and liver injury after taking a mixed supplement containing Tongkat Ali.

However, the cause was likely multifactorial, possibly related to product contamination or anabolic steroids, rather than Tongkat Ali itself [5].

Regarding gastroparesis, there is no medical evidence linking Tongkat Ali to this condition. Clinical studies and safety reviews have not reported any nerve-related side effects similar to gastroparesis.

In the LiverTox case report, the individual experienced stomach pain, nausea, vomiting, and liver injury after using a combination supplement containing Tongkat Ali — but this case does not establish a direct link between Tongkat Ali and gastroparesis [5].

6. Can You Be Allergic to Tongkat Ali?

Yes, it’s possible — particularly due to proteins in the extract or impurities. In the EFSA report “Safety of Eurycoma longifolia root extract,” the authors noted that the extract can contain up to ~45% protein, meaning there is a potential for allergic reactions, although no confirmed allergy cases were reported in clinical studies conducted in Malaysia, where the plant originates [9].

In a clinical trial review (Leisegang et al., 2022), reported side effects included digestive symptoms and itching — with “itching” considered a mild skin allergy indicator [10].

According to LiverTox, “rash” is listed among the rare adverse reactions that may occur with Tongkat Ali use [5].

7. Can Tongkat Ali Cause a Rash?

It may cause mild rashes or skin irritation in sensitive individuals or those using low-quality products. LiverTox lists “rash” as one of the possible side effects of Tongkat Ali [5].

In the study by Leisegang et al. (2022), reported adverse effects included “itching,” which may occur along with mild skin rashes [10].

8. Does Tongkat Ali Cause Bloating?

There is no strong clinical evidence that Tongkat Ali causes bloating. However, in some individual cases or when products contain impurities, bloating may occur.

In official reports such as LiverTox, EFSA, and clinical trials, bloating is not listed as a known side effect of Tongkat Ali [5].

Effects on Psychology and the Nervous System

1. Can Tongkat Ali Cause Anxiety?

There is no convincing evidence that Tongkat Ali increases anxiety; in fact, several studies report that it may help reduce stress and anxiety.

Some human clinical trials have shown that Tongkat Ali supplementation can lower cortisol levels (the stress hormone) and improve anxiety/stress scores compared with placebo.

Systematic reviews indicate that its overall mood effects are neutral or beneficial rather than anxiety-inducing.

If anxiety symptoms occur, they are likely due to individual reactions, excessive dosage, or impure products [11].

2. Why Do I Experience Shaky Hands, Anxiety, and Brain Fog When I Miss a Dose of Tongkat Ali?

There is no clear scientific evidence of a specific “withdrawal syndrome” associated with Tongkat Ali.

The symptoms described may result from hormonal or mood fluctuations, psychological effects (placebo/nocebo), or other unrelated causes.

Because Tongkat Ali can influence testosterone and cortisol, sudden changes in hormonal balance—especially in long-term or high-dose users—may cause temporary sensations when discontinued.

However, medical literature does not describe “hand tremors upon withdrawal” as a known effect of Tongkat Ali.

Additionally, contaminated products (e.g., with heavy metals like mercury) could cause neurological issues such as tremors or brain fog, which should also be considered [11].

3. Has Anyone Experienced Severe Anxiety or Tremors from Taking Tongkat Ali?

No peer-reviewed case reports have documented severe anxiety or tremors directly caused by Tongkat Ali.

Some anecdotal reports exist on online forums and social media, but these are not scientific evidence.*

Databases such as LiverTox list mild side effects (e.g., headache, nausea, diarrhea, rash) but do not include severe tremors or intense anxiety as common reactions.

If someone experiences significant tremors or severe anxiety while taking Tongkat Ali, it is advisable to stop use and seek medical advice immediately [5].

4. Can Tongkat Ali Cause Depression?

There is no scientific evidence that Tongkat Ali causes depression. Small clinical trials using standardized extracts such as Physta® have shown reduced stress, less fatigue, and improved quality of life—rather than increased depressive symptoms.

If low mood occurs after use, it may result from individual sensitivity, hormonal fluctuations, drug interactions, or product contamination [11, 12, 13].

5. Why Do Some Users Report Depression or Low Mood While Taking Tongkat Ali?

Possible causes include individual differences, drug interactions, high doses, psychological (nocebo) effects, or poor product quality (impurities or heavy metals).

Anecdotal reports exist, but no systematic studies confirm this as a common side effect.*

The mechanism could involve hormonal changes (testosterone, estrogen, cortisol) that affect mood in some individuals, or reactions to non-pure ingredients [11, 12, 13].

6. Can Tongkat Ali Cause Depression, Fatigue, or Low Energy in Some Users?

This is uncommon; most studies report reduced fatigue and improved energy.

Clinical trials using Physta® and other short-term studies have shown decreased tiredness and enhanced quality of life.

If some users feel tired or low in energy, other causes should be considered (e.g., lack of sleep, medication interactions, or hormonal shifts) [12, 13].

7. Does Tongkat Ali Affect Brain Fog?

There is no evidence that Tongkat Ali causes brain fog.

Some studies even report improved mental clarity and energy, although data specifically on “brain fog” are limited.

Since brain fog is a subjective symptom, other possible causes should be evaluated—such as poor sleep, nutrient deficiencies, medication effects, or product contamination.

Human studies rarely report adverse cognitive effects; in fact, some suggest cognitive and mood benefits [11, 14].

8. Does Tongkat Ali Affect Thyroid?

There is no strong evidence of a direct effect on the thyroid in humans.

Most research focuses on testosterone, cortisol, and stress-related or reproductive markers.

Some non-clinical or animal studies suggest that Tongkat Ali may influence endocrine regulation, but clinical data are insufficient to confirm any effect on TSH, T3, or T4 levels in humans.

Individuals with thyroid disorders should consult their healthcare provider before using Tongkat Ali [9, 15].

9. Does Tongkat Ali Affect Sleep?

It may — depending on the individual and timing.

Some studies show that Tongkat Ali can improve sleep quality, while animal studies report both alertness-enhancing effects and improved NREM sleep during rest phases.

Human and animal trials suggest potential benefits for sleep quality and reduced daytime fatigue, but recent animal studies (2023–2024) also describe a “wake-enhancing” effect during the active phase.

This means its effect on sleep depends on dosage and timing: taken in the morning or daytime, it may enhance energy; taken late, it might disrupt sleep in sensitive users [13, 16, 17].

10. Why Do Some People Report Difficulty Sleeping When Taking Tongkat Ali?

Possible causes include its mild stimulating or alertness-enhancing effects, taking it close to bedtime, high dosage, or individual sensitivity.

Animal studies show that Tongkat Ali can increase alertness during certain activity phases, and some clinical surveys note insomnia or restlessness in users who take it late in the day or at high doses.

Poor-quality or contaminated products may also cause nervous system stimulation [5, 16, 17].

11. Does Taking Tongkat Ali at Night Affect Sleep Quality?

It can. If you are sensitive to stimulants, it is best not to take it close to bedtime.

Because Tongkat Ali may increase alertness—especially at higher doses—taking it in the evening may lead to difficulty falling asleep.

Experts generally recommend taking it in the morning or early afternoon.

Some studies show overall improvements in sleep quality when dosage and timing are appropriate, but timing remains a key factor [16, 17].

12. Does Tongkat Ali Cause Insomnia?

Not commonly, though some users may experience insomnia when taking it late in the day or at high doses.

Large clinical trials do not list insomnia as a frequent side effect, but both anecdotal reports and animal studies suggest that improper timing or dosing may contribute to sleep disturbances.

If you are prone to insomnia, avoid evening doses [5, 16].

13. Why Does Tongkat Ali Cause Insomnia?

Possible mechanisms include its energy-boosting and alertness effects, influence on the central nervous system, or inappropriate dosage or product formulation.

Some compounds in Tongkat Ali may enhance energy and affect thermoregulation or circadian rhythm, leading to increased wakefulness.

When taken late, this may interfere with sleep.

Interactions with stimulants (e.g., caffeine or certain medications) can also worsen the problem [11, 16, 17].

14. Why Do Some People Report Insomnia or Restlessness While Taking Tongkat Ali?

Due to individual sensitivity, high doses, late dosing, drug interactions, or poor product quality.

Personal factors and product purity are important considerations.

If the product contains stimulant-like impurities or heavy metals, symptoms such as restlessness or anxiety may occur.

If this happens, try lowering the dose or switching to morning use [5, 18].

15. Will Tongkat Ali Keep Me Awake?

Unlikely for most users if taken in the morning.

However, if you are highly sensitive or take it late or at high doses, it may interfere with sleep [16, 17].

16. Can Tongkat Ali Make You Tired?

Most research shows the opposite — Tongkat Ali generally reduces fatigue and improves energy.

Clinical trials (e.g., with Physta®) report reduced fatigue and improved quality of life.

However, some users may feel tired due to medication interactions or hormonal adjustments when starting or stopping use [12, 13].

17. Why Do I Feel Depressed, Unmotivated, or Low Energy After Stopping Tongkat Ali?

This may be due to biological mechanisms (hormonal shifts) or a rebound/psychological effect, though no controlled studies have quantified a “crash” after discontinuation.

Because Tongkat Ali can influence testosterone and cortisol, abrupt cessation may cause a temporary sense of imbalance or low energy.

However, no systematic research has confirmed this phenomenon.

A practical approach is to taper the dose gradually, ensure proper sleep and nutrition, and consult a healthcare provider if symptoms persist [11].

18. Is the “Crash” After Stopping Tongkat Ali Common?

No. There is no scientific evidence that a “crash” is a common or well-defined withdrawal effect.

Anecdotal reports exist but lack formal validation, so it cannot be considered a typical reaction.

If concerned, taper gradually and seek medical guidance [5].

19. How Long Does It Take to Feel Normal After Discontinuing Tongkat Ali?

There are no precise data from clinical studies.

If symptoms arise from temporary hormonal adjustments, they usually resolve within a few days to a few weeks.

Because no systematic studies exist, recovery time likely depends on dosage, duration of use, and individual factors such as product purity.

Many anecdotal reports describe improvement within 1–2 weeks, though this is not standardized clinical evidence [11, 17].

20. Are There Ways to Stop or Reduce the Post-Use Crash?

Some reasonable but untested strategies include:

• Gradually taper the dosage instead of stopping abruptly.

• Maintain good sleep, nutrition, and exercise habits.

• Check for potential drug interactions.

• Use high-quality, tested products to avoid contaminants.

• Consult a healthcare professional if symptoms are severe or persistent.

These are general good-practice recommendations when discontinuing any substance that influences hormones or mood.

If contamination (e.g., heavy metals) is suspected, stop use and consider appropriate medical testing [9, 11, 18].