Tongkat Ali vs Ashwagandha: Best for Testosterone?

Mike HartnettEvidence-Based

7+ years researching longevity protocols. Runs a 20+ supplement daily stack. Built CoreStacks after losing his father to heart disease.

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Tongkat Ali vs Ashwagandha at a Glance

What Is Tongkat Ali?

Tongkat Ali (Eurycoma longifolia) is a Southeast Asian plant that has been used in traditional medicine for centuries, mainly as an energy and libido booster. Modern research shows why: it targets testosterone through two specific mechanisms that most “testosterone boosters” only dream about.

First, it reduces sex hormone-binding globulin (SHBG). SHBG is the protein that binds to testosterone and makes it unavailable to your tissues. You can have solid total testosterone numbers but still feel like garbage if your SHBG is eating most of it. Tongkat Ali lowers SHBG, which directly increases the amount of free testosterone circulating in your blood. Second, it supports luteinizing hormone (LH) signaling, which tells your testes to produce more testosterone upstream. A 2012 study in the Journal of the International Society of Sports Nutrition found significant improvements in testosterone profiles and stress hormones in moderately stressed adults after 4 weeks of supplementation.

Andrew Huberman has discussed Tongkat Ali specifically on the Huberman Lab podcast, recommending 400mg per day as part of his hormone optimization protocol. He cycles it — and that cycling part matters. Unlike most supplements, Tongkat Ali can cause restlessness, insomnia, or overstimulation if you run it continuously without breaks. Five days on, two days off. Or eight weeks on, two weeks off. Either schedule works. For Huberman’s full approach, see our Huberman supplement stack breakdown.

What Is Ashwagandha?

Ashwagandha (Withania somnifera) is an adaptogen with one of the deepest research bases of any herbal supplement. KSM-66 is the patented root extract with the most clinical backing, and the results are consistent across dozens of trials: it significantly reduces cortisol levels, lowers anxiety, improves sleep quality, and supports testosterone — all as downstream effects of getting your stress hormones under control.

With ashwagandha and testosterone. A 2019 randomized controlled trial published in the American Journal of Men’s Health found that men taking 600mg of ashwagandha root extract daily for 8 weeks showed significant increases in testosterone and DHEA-S levels compared to placebo. But the mechanism is indirect. Ashwagandha doesn’t directly stimulate testosterone production the way Tongkat Ali does. It reduces cortisol — and since cortisol and testosterone have an inverse relationship, lowering one raises the other. If your testosterone is suffering because you’re chronically stressed, sleeping poorly, and running cortisol around the clock, ashwagandha addresses the root cause.

The versatility is what makes ashwagandha so popular. It handles anxiety, sleep quality, cortisol management, and hormonal support in a single supplement. That’s why it shows up in so many expert stacks — not just for testosterone, but as a general-purpose adaptogen. If you want to see how it compares to other stress-focused supplements, check our ashwagandha vs rhodiola comparison and ashwagandha vs L-theanine for anxiety.

Key Differences Between Tongkat Ali and Ashwagandha

Direct vs Indirect Testosterone Support

This is the fundamental distinction. Tongkat Ali works directly on your testosterone machinery — SHBG reduction and LH stimulation. It doesn’t care about your stress levels or cortisol. It targets free testosterone mechanically. Ashwagandha works on testosterone indirectly by fixing the cortisol problem. If your testosterone is low because of chronic stress, ashwagandha addresses the cause. If your testosterone is low because of high SHBG, Tongkat Ali is the smarter tool. Two different problems, two different solutions.

Cycling Requirements

Look, this matters for real-world compliance. Tongkat Ali needs to be cycled. Huberman himself cycles it — and multiple researchers recommend breaks to prevent receptor desensitization and manage side effects like insomnia. Ashwagandha doesn’t require cycling. The clinical trials that demonstrate its benefits ran continuously for 8–12 weeks, and long-term use is generally well-tolerated. If you’re someone who doesn’t want to track on/off schedules, ashwagandha is the simpler option.

Scope of Benefits

Tongkat Ali is a specialist. It does testosterone and libido well, and some research shows modest cortisol-lowering effects, but it’s primarily a hormonal supplement. Ashwagandha is a generalist. Anxiety reduction, sleep improvement, cortisol management, exercise performance, and testosterone support all come in the same capsule. If you’re only dealing with one issue (low free T), the specialist might be better. If you’ve got three or four overlapping issues, the generalist covers more ground.

Side Effect Profiles

Tongkat Ali can cause insomnia, restlessness, and irritability — especially at higher doses or without cycling. It’s stimulating by nature, which is great for energy and drive but can backfire at bedtime. Ashwagandha tends in the opposite direction — it can cause drowsiness in some people, which is why many take it in the evening. Occasional GI discomfort in the first week is common. There’s also a rare but documented interaction with thyroid function — ashwagandha can raise thyroid hormone levels, so anyone with hyperthyroidism should proceed carefully.

Can You Stack Tongkat Ali and Ashwagandha?

Yes — and this is a legitimate combination. Since they work through completely different pathways (SHBG/LH vs cortisol/HPA axis), they’re complementary without redundancy. You’d get direct free testosterone optimization from Tongkat Ali plus cortisol management and stress resilience from ashwagandha. Huberman has discussed both positively, though not necessarily as a combined stack.

The practical consideration: watch for overstimulation. If Tongkat Ali is already giving you an energy boost and you add ashwagandha’s sometimes-stimulating initial effects, some people feel wired for the first week. Start ashwagandha alone for two weeks, then add Tongkat Ali on your regular cycling schedule. Use our supplement interaction checker to verify the combination with everything else in your stack.

What Experts Say

Andrew Huberman has discussed both extensively on the Huberman Lab podcast. He specifically recommends Tongkat Ali at 400mg/day, cycled, for testosterone support. He’s called it one of the more evidence-backed options for free testosterone. He also acknowledges ashwagandha’s broad adaptogenic benefits, particularly for cortisol and anxiety. His full supplement stack includes Tongkat Ali as a core hormonal support.

Peter Attia has discussed hormone optimization on The Drive podcast, noting that lifestyle factors (sleep, exercise, body composition) account for far more testosterone variance than any supplement. His longevity protocol prioritizes these fundamentals. For a broader view of how top experts structure their approaches, see our expert stacks comparison.

Dr. Brad Stanfield has reviewed ashwagandha on his evidence-based YouTube channel, calling the KSM-66 clinical data compelling for cortisol and anxiety. He’s more cautious about Tongkat Ali, noting the evidence is growing but not yet as strong as ashwagandha’s. See our Stanfield protocol breakdown for his complete approach.

Which Should You Choose?

Choose Tongkat Ali if testosterone optimization is your primary goal and your cortisol/stress levels are already under control. You want direct SHBG reduction and LH support. You’re comfortable with cycling (5 days on, 2 off). Take 200–400mg of standardized extract daily.

Choose ashwagandha if you’re dealing with chronic stress, anxiety, poor sleep, or generally feeling burned out — and the low testosterone is a downstream symptom. KSM-66 at 600mg/day addresses the root cause. No cycling required.

Choose both if you want to cover both pathways — direct testosterone support plus cortisol management. Run ashwagandha daily and cycle Tongkat Ali on top of it.

Before adding either supplement, getting blood work is worth it — you need to know whether your testosterone issue is a free T problem (high SHBG), a total T problem, or a cortisol/stress problem. The right supplement depends on the right diagnosis. Check our blood tests guide for exactly which panels to order.

Frequently Asked Questions

This article is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement regimen.