Bulbine Natalensis.
South African herb with testosterone-boosting claims May support testosterone levels and sexual function (animal data)
Reviewed March 2026
- Category
- Herb
- Also filed under
- TestosteroneLibidoRecovery
What Bulbine Natalensis is, and what it does.
- Does it work
- Interesting animal studies but human evidence is very weak. Risky for liver.
- How much to take
- Start with 250 to 500mg a day of a named plant part. The 1,000mg used in studies is a research condition, not a daily target. Extraction ratio tells you more than the milligrams.
- Time to feel it
- Nobody has measured a human timeline for this plant. The published record is mostly rodent work, so there is no reliable number of days or weeks to give you.
- The first dose
- Day one is quiet. No same-day marker has been measured for this plant in people, so the first 24 hours are about tolerance rather than effect.
- With regular use
- Unclear. May affect testosterone. Liver concerns with prolonged use.
- How well tolerated
- Potential liver and kidney toxicity at high doses or long-term use.
- How it feels
- Variable. Some report increased drive, others nothing.
- The overlooked benefit
- There is no marker compound to standardise against here, so the label details that carry real information are the plant part, the extraction ratio and what the batch was tested for.
250 to 500mg a day is where Bulbine Natalensis works.
Source: Yakubu et al. (2008) Indian J Exp Biol; only rat studies available
The proof, claim by claim.
These words describe the research, not the molecule's worth. Research strength is how much work stands behind one claim, and it is never a product score.
Bulbine Natalensis has emerging evidence. Based on 52+ studies.
- Hormone and reproductive organ markers in rodentsAnimal study
- Liver and kidney marker changes in rodents at higher intakesAnimal study
- Anthraquinone, saponin and phenolic glycoside content of the plantIn vitro study
- Traditional southern African use of the stem and rootNarrative review
Questions people ask about Bulbine Natalensis.
- When should I take it?
- Timing matters less than consistency. Pick a time that works for you and take it daily.
- Can I take it with other supplements?
- Usually fine. The main thing to watch is not doubling up on the same ingredient from different products. If you're on prescription meds, check with your pharmacist first.
- Any side effects to watch for?
- Most people tolerate it well at recommended doses. GI upset is the most common complaint with any supplement. Start with a lower dose and work up. If something feels off, stop and reassess.
- Who benefits most from this?
- Honestly, most people would benefit more from the basics. But if you've got a specific reason to try it, the risk is generally low.
Why these belong in the same formula. Each row says what the basis is, from settled biochemistry through to a trial that measured the pair.
Zinc is a required cofactor for the enzymes of normal androgen synthesis and for gonadotropin signalling. A botanical aimed at that axis has no effect to build on if the underlying mineral cofactor is short.
Bulbine natalensis and ashwagandha appear together in men's botanical formulas, each brought in for a different traditional rationale rather than for a demonstrated interaction. Ashwagandha has the larger human literature of the two by a wide margin. No trial has tested the combination. The pairing is formulation convention.
Tongkat ali is the other botanical that most often shares a label with Bulbine natalensis in men's formulas. The two come from different continents and different traditional systems, and are combined by formulators rather than by any shared history of use. Nothing has been published on the combination. Read it as a category pairing.
Panax ginseng is a frequent partner in the same product category, carrying a far larger clinical literature of its own. Placing them together does not transfer that evidence to Bulbine natalensis. The pairing is a formulation choice and should be described as one.
Boron influences steroid hormone binding and metabolism in human studies at modest intakes, and it is a routine mineral partner in the formulas Bulbine natalensis appears in. The two act through unrelated mechanisms, so the pairing is additive rather than interactive. Neither depends on the other. The evidence for boron here rests on hormone markers, not on outcomes.
Vitamin D status is associated with steroid hormone measures in observational work, which is an association and not a demonstrated cause. It is a common mineral and vitamin base in the formulas this botanical is sold in. The two contribute independently. Vitamin D belongs in such a formula on its own nutritional grounds.
Magnesium is a cofactor across hundreds of enzymes and has been studied in relation to hormone binding protein measures. It is a standard base mineral in the category rather than a partner with a specific interaction with this botanical. The contributions are separate. State it as co-formulation.
Piperine inhibits intestinal and hepatic drug-metabolising enzymes and transporters, which raises circulating levels of many co-administered compounds. Applied to a botanical whose constituent profile and dosing are poorly characterised, that cuts both ways: it can raise exposure to the desired constituents and to everything else in the extract at the same time. No study has looked at piperine with this plant. Regard the combination as a reason for caution rather than a claim.
Rodent work on Bulbine natalensis extracts has reported dose-related changes in liver and kidney biochemical markers at higher intakes, which is why formulators sometimes pair it with a hepatoprotective botanical. Those are animal marker findings and do not establish what happens in people. Adding milk thistle does not neutralise an unquantified exposure and should not be presented as doing so. The honest reading is that this plant's dose response in humans has not been characterised.
Citrulline is converted to arginine and feeds nitric oxide synthase, supporting normal blood flow through a route unrelated to anything this botanical is proposed to do. The two are combined in performance formulas for that separation of mechanisms. The citrulline arm has its own human evidence; the botanical arm does not carry over to it.
Zinc is required across steroidogenic enzymes and is one of the minerals whose deficiency measurably changes hormone markers, which is why it is a routine mineral in this product category. Hormone markers are markers, not outcomes. Zinc contributes on its own nutritional grounds rather than through any characterised interaction with the botanical. No study has tested the two together.
Nothing specific on file for Bulbine Natalensis. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.What Bulbine Natalensis actually does.
Bulbine natalensis is a succulent in the Asphodelaceae family from southern Africa, the same family as Aloe, and its stems and roots are the parts used traditionally.
Anthraquinone glycosides are largely inactive until gut bacteria cleave the sugar to release the aglycone, so the effect of a plant carrying them depends on the individual microbiota as well as on the dose.
Extract strength for this plant is set by the plant part used, the solvent and the concentration ratio rather than by a standardised marker compound, so two products declaring the same milligram amount are not delivering the same thing.
Asphodelaceae species including Bulbine characteristically contain anthraquinones and their glycosides, along with saponins and phenolic glycosides; the anthraquinone class is the same chemistry that makes several related plants act on the bowel.
Where Bulbine Natalensis comes from.
The plant is harvested, washed and dried, then either ground into a powder or soaked in water or alcohol to pull out its compounds before that liquid is dried back to a powder. Because nobody has settled on one compound to measure, two products can be made from the same plant and still not contain the same amounts. What the label can tell you is the plant part, the extraction ratio and what it was tested for.
Made from a plant. What ends up in the capsule tracks the harvest, so batch testing and a stated marker matter more here than with a made molecule.
A succulent perennial of southern Africa, grown in sandy well-drained soil or gathered from wild stands; stems and roots are the parts taken for oral material.
Plant material is cleaned of soil, cut and dried at controlled temperature to bring moisture down far enough that microbial growth and enzymatic breakdown stop.
Dried material is either milled straight to a powder, or extracted with water or a water and ethanol mixture, then filtered and concentrated under reduced pressure.
The concentrate is spray-dried or vacuum-dried, usually onto a carrier such as maltodextrin or rice flour to give a handleable free-flowing powder.
Batches are declared either as a plant-to-extract ratio or against a named constituent class; identity is confirmed by botanical or chromatographic means and the material is tested for heavy metals, pesticides and microbial limits.
The finished powder is blended and filled into capsules or compressed into tablets, typically alongside minerals and other botanicals in the same category.
Getting Bulbine Natalensis from food.
The whole-food sources on file. A supplement closes the gap, it does not replace dinner.
A gram-for-gram figure (how much of each you would eat to match a dose) will appear here once it is sourced and reviewed. This page will not print a number it cannot cite.
The forms it comes in.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.