Ingredient
Tribulus in Protoflow: 120 mg a Serving
Tribulus terrestris is a ground-hugging plant whose fruit is sold to support testosterone and sexual function, and Protoflow lists 120 mg per serving. Memorial Sloan Kettering calls the data on testosterone and erectile function mixed and lists rare case reports of serious harm.
Written by the Protoflow label teamUpdated
The plant01
What is tribulus?
Tribulus (Tribulus terrestris) is a low, spiny plant found in warm regions worldwide, and its fruit and root are sold as a supplement for testosterone and sexual function.
The Protoflow label prints "Tribulus", 120 mg, line 8 of 14. The sales page does not name it, so it is another line found only by reading the label. The amount matches ginkgo and Chinese ginseng.
The label gives no plant part and no standardization. Many tribulus products are standardized to saponins, the compounds researchers track, and a product that is not may carry far less.
| Name on the label | Tribulus (Fruit) |
|---|---|
| What it is | Tribulus terrestris fruit |
| Place on the label | 9 of 14 |
| Amount per serving (2 capsules) | 120 mg |
| Per capsule, if split evenly | 60 mg (the label does not say) |
| % Daily Value | Not established |
| Named on the sales page? | No |
| Amount used in research | No consistent dose |
| Strength of evidence | Mixed for testosterone and erectile function |
| Marketed or traditional use | Marketed for sexual function and body building |
| Main caution | May add to diabetes and blood pressure drugs (MSK); rare severe liver and kidney reports. |
Evidence02
Does tribulus raise testosterone?
Memorial Sloan Kettering reports that testosterone effects are mixed, with increases only in combination products (MSK, Tribulus terrestris).
That detail echoes the damiana story. When a benefit shows up only in blends, you cannot say which ingredient caused it, or whether the blend did anything at all beyond chance. Data on erectile dysfunction are also mixed.
The prostate is a separate question and the answer is short. We found no trial of tribulus for an enlarged prostate or urinary flow. Its reputation is built on testosterone, and testosterone is not a tool for treating urinary symptoms. For men whose prostate is already enlarged, a doctor may in fact want to know before any testosterone-related product is used.
Safety03
Is tribulus safe?
Most people report stomach irritation or reflux, but MSK also lists case reports of severe liver, kidney and neurological toxicity and of priapism (MSK, Tribulus terrestris).
Case reports prove little about how often something happens. They do justify caution, especially for the liver. Niacin at 75 mg in the same formula can also strain the liver at high doses over time (NIH ODS, Niacin), so liver health is one more reason to speak to a doctor first.
MSK also notes tribulus may have additive blood-sugar-lowering effects and may add to blood pressure drugs, though the clinical relevance is not known (MSK, Tribulus terrestris). Prostate cancer patients are told to consult physicians first (MSK, Tribulus terrestris).
Get urgent help for a painful erection that lasts several hours, for yellow skin or eyes, or for very dark urine. These need emergency care, not a bottle or a website.
See a doctor today
- You cannot pass urine at all, or only a few drops with a full, painful bladder
- Blood or clots in the urine
- Fever or chills with burning or painful urination
- Severe pain in the lower belly, back or genitals
- A sudden change after a fall or injury
Book an appointment
- A weak or slow stream, or stopping and starting
- Needing to go again soon after you finish
- Waking more than usual at night to urinate
- A sudden, strong urge that is hard to hold
- Dribbling after you finish
- A new erection problem, or a PSA you have not discussed
Urinary symptoms can come from an enlarged prostate, infection, diabetes, medicines, sleep apnea, and sometimes cancer. Lists drawn from NIDDK (NIDDK, Enlarged Prostate (BPH)) and MedlinePlus (MedlinePlus, Nocturia). A supplement cannot sort these causes out.
At a glance04
How does tribulus fit the Protoflow claims?
It fits a vitality story and does not fit the flow story, since no study connects it to urine flow.
| Point | What is known |
|---|---|
| Amount | 120 mg per serving, not on the sales page |
| Testosterone | Mixed; increases only in combination products (MSK, Tribulus terrestris) |
| Erectile function | Mixed data (MSK, Tribulus terrestris) |
| Blood sugar and pressure | May add to medicines; relevance unknown (MSK, Tribulus terrestris) |
| Rare serious reports | Liver, kidney, neurological, priapism (MSK, Tribulus terrestris) |
| Prostate trial | None found |
Protoflow: from $49 a bottle60 capsules · 2 a day · free US shipping on 3 or 6 · 60-day money-back guarantee
See packsReading the label05
Why does the label not name the tribulus extract?
The label does not say, and the likeliest reason is that US supplement rules do not require makers to print extract details on the panel.
A supplement label must list ingredients and amounts, but it does not have to state the plant part, the extract ratio or the content of marker compounds. Some makers print them and some do not. This one does not. The FDA is not authorized to approve supplements before sale (FDA, Information for Consumers on Supplements), so no regulator checks that a "120 mg" line contains what a study used.
For tribulus the gap matters more than usual. The compounds that products are standardized to, saponins, vary widely between brands. The result is that two products with the same word and weight on the label can act very differently, and the trial results for one do not carry over to the other.
What you can do as a buyer is limited but real. You can ask for a certificate of analysis for the lot and read it. You can look for third-party seals that name the testing body, and check the body's site for the product. The Protoflow pack shows a lot number and a certificate reference, which we report as seller references, not as proof (see the batch page).
You can also weigh whether a product that cannot name its extract is worth a six-month supply. The 2-bottle pack exists for a trial of the formula, with the 60-day guarantee as the safety net. If you decide to try it, write down your starting symptoms so that the end of the trial is a comparison and not a memory.
Finally, remember the point about men with an enlarged prostate. Your doctor may use PSA to track you (NCI, PSA Test), and anything that changes hormones or the prostate deserves a mention at that visit.
Asking first06
Who should check with a doctor before taking tribulus?
Anyone with liver or kidney disease, diabetes, high or low blood pressure, or a prostate cancer history should check with a doctor before using a formula that lists tribulus.
The same goes for men on blood pressure or diabetes medicine. Bring the label and say what you take. Keep taking prescribed medicine as directed.
For catuaba, the next herb, see the catuaba page, or compare all lines on the supplement facts page.
FAQ07
Tribulus in Protoflow: questions answered
Is tribulus in Protoflow?
Yes. The label lists tribulus at 120 mg per serving, line 8 of 14. The sales page does not name it, so only the label shows it.
Does tribulus boost testosterone?
The evidence is mixed. Memorial Sloan Kettering reports increases only in combination products, so a single-herb effect is not shown.
Can tribulus harm the liver?
MSK lists case reports of severe liver and kidney toxicity. These are rare reports, not measured rates, but they justify asking a doctor first.
Does tribulus help the prostate?
We found no trial of tribulus for the prostate or urinary flow. Its research is about testosterone and sexual function.
What are the side effects of tribulus?
Stomach irritation and reflux are reported, plus rare serious cases. Seek urgent care for a painful erection lasting hours or yellow skin.
Can tribulus interact with medicines?
It may add to blood sugar and blood pressure medicines, though the relevance is not known. Ask your pharmacist to check your list.
Who wrote this08
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by a USA authorized retailer of Protoflow, not by the manufacturer or the label distributor. Buying through our order links earns us money.
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