Ingredient
Tribulus in Protoflow: 120 mg, and a Testosterone Claim the Evidence Does Not Support
Tribulus in Protoflow is 120 mg of tribulus fruit per 2-capsule serving. It is sold on the belief that it acts like testosterone, but Memorial Sloan Kettering says the evidence does not clearly support that. Human results on sexual function are mixed, and case reports describe liver, kidney and nerve harm.
Written by the Protoflow label deskUpdated
The ingredient01
What is tribulus in Protoflow?
Tribulus is Tribulus terrestris, a vine sold for libido. The Protoflow panel lists it as Tribulus (Fruit), 120 mg per 2 capsules.
It sits in the "libido tradition" group of the formula, next to epimedium, damiana, muira puama and catuaba. The sales page leaves tribulus out of its list of eight botanicals (Protoflow info page).
The panel is the legal record of what is in the capsule, so we follow it (Protoflow bottle label). The bottle makes no written claim about tribulus.
Why men look for it
Tribulus is sold for libido and testosterone (MSK, Tribulus terrestris). The sources we cite give no prostate finding, so the testosterone claim is the one to check.
Dose check02
How much tribulus is in Protoflow?
A serving holds 120 mg of tribulus fruit, which is 60 mg a capsule and about 7% of the 1,619 mg total.
It is the same size as ginkgo and Chinese ginseng at 120 mg each. The label allows 2 capsules a day, so 120 mg is the whole daily amount.
The MSK review gives no established dose for tribulus, so we cannot call 120 mg low or high (MSK, Tribulus terrestris). What we can check is the claim behind the herb.
120 mg
Fruit, per 2 capsules.
No set dose
No dose is established in the review we cite.
Label silent
The bottle names no tribulus benefit.
The claim03
Does tribulus work like testosterone?
The evidence does not clearly support it. Tribulus is marketed on the belief that it acts like testosterone, and MSK says the data fall short.
Human studies of testosterone are mixed. One study of athletes found that tribulus alone did not improve androgen status or performance. Evidence for sexual function in men is also mixed (MSK, Tribulus terrestris).
| Claim | What MSK found |
|---|---|
| Acts like testosterone | The evidence does not clearly support this |
| Changes testosterone in people | Human studies are mixed |
| Improves athletes' androgen status | One athlete study found no gain from tribulus alone |
| Helps sexual function | Human evidence is mixed |
For that reason this site does not say Protoflow raises hormone levels, and the label does not either.
Testing04
How do you know if your testosterone is low?
A doctor checks with blood tests, not with a supplement. Low sex drive, muscle loss and infertility can have several causes.
MedlinePlus says hypogonadism is diagnosed with a physical exam and blood tests for testosterone and related hormones. It is harder to judge in older men, whose levels decline gradually, and in obese men. Treatment is typically testosterone replacement, prescribed by a clinician (MedlinePlus, Male Hypogonadism).
Low desire and erection trouble can also come from vascular disease, diabetes, some medicines, drinking, smoking and stress (NIDDK, Erectile Dysfunction).
If you suspect low testosterone, ask for the blood test. A supplement cannot tell you what your levels are, and it could hide a problem that needs care.
Protoflow: from $49 a bottle60 capsules · 2, 3 or 6 bottles · free US shipping on 3 or 6 · 60-day guarantee
See packsSafety05
Is tribulus safe, and what are its side effects?
Stomach irritation is the usual effect. MSK also lists case reports of liver, kidney and nerve toxicity and one 72-hour painful erection.
Case reports cannot prove tribulus was the cause, but they are why we mention them. A painful erection that lasts hours needs urgent care.
| Concern | What the source says |
|---|---|
| Blood pressure medicine and diuretics | Tribulus may add to their effects; clinical relevance unknown (MSK, Tribulus terrestris) |
| Diabetes medicine | It may add to antidiabetic drugs; clinical relevance unknown (MSK, Tribulus terrestris) |
| Prostate cancer | Ask a physician first because of possible hormonal activity (MSK, Tribulus terrestris) |
| Liver, kidney, nerves | Case reports of toxicity (MSK, Tribulus terrestris) |
Keep taking prescribed medicine and tell your prescriber about Protoflow. See side effects for the whole formula.
At a glance06
What does the tribulus line show next to the research?
One table: the label wording, the amount, the studied dose and the main caution.
FDA has found hidden sildenafil and tadalafil in "natural" products sold for male performance (FDA, Alpha-Male public notification). We know of no such finding for Protoflow, and a label alone cannot rule it out. Read male vitality supplement safety.
| Name on the label | Tribulus (Fruit) |
|---|---|
| What it is | Tribulus terrestris, a vine sold for libido |
| Place on the label | Its own printed line |
| Amount per 2 capsules | 120 mg per 2 capsules |
| Amount per capsule | 60 mg |
| Amount used in research | No established dose |
| Strength of evidence | Evidence does not clearly support a testosterone-like action |
| Marketed or traditional use | Sold for libido and testosterone |
| Main caution | Stomach irritation; case reports of liver, kidney and nerve toxicity and one long painful erection. |
Verdict07
How should you weigh tribulus in Protoflow?
As a small, unproven line whose famous claim the evidence does not clearly back.
Fair points
- The 120 mg amount is printed
- The label makes no testosterone claim
Weak spots
- Testosterone-like action not clearly supported
- Rare serious case reports
- No product trial
The other lines are on the ingredients page.
FAQ08
Tribulus in Protoflow: common questions
Does tribulus terrestris raise testosterone?
Not clearly. MSK says tribulus is marketed as acting like testosterone, but the evidence does not clearly support this. Human studies are mixed, and an athlete study found no gain in androgen status from tribulus alone (MSK, Tribulus terrestris).
How much tribulus fruit is in Protoflow?
A 2-capsule serving holds 120 mg of tribulus fruit, or 60 mg a capsule. That equals the ginkgo and Chinese ginseng lines. The review we cite sets no established dose, so 120 mg cannot be graded as high or low.
Does tribulus help with low libido?
The evidence is mixed. MSK reports mixed human results for sexual function in men (MSK, Tribulus terrestris). Low desire can come from low testosterone, medicines, stress or disease, and a doctor can sort those out with a visit and blood tests (MedlinePlus, Male Hypogonadism).
Can a blood test show whether my testosterone is low?
Yes. Doctors diagnose low testosterone with a physical exam and blood tests for testosterone and related hormones. It is harder to judge in older or obese men, so ask for a clinician's read, not an online quiz (MedlinePlus, Male Hypogonadism).
What are the side effects of tribulus?
The common effect is stomach irritation. MSK also lists case reports of liver, kidney and nerve toxicity and a 72-hour painful erection (MSK, Tribulus terrestris). Stop the capsules and call a clinician if any serious symptom appears.
Is tribulus safe for men with prostate cancer?
Ask a physician first. MSK advises men with prostate cancer to check with a doctor because tribulus may have hormonal activity (MSK, Tribulus terrestris). That caution applies to any capsule containing it, Protoflow included.
Can tribulus affect blood pressure or diabetes medicine?
Possibly. MSK says tribulus may add to the effects of blood pressure drugs, diuretics and diabetes medicine, though the clinical relevance is unknown (MSK, Tribulus terrestris). Tell your prescriber about Protoflow before you start.
Who wrote this09
Written and reviewed by
Pages built from the label, the brand pages and linked NIH, FDA, FTC, NICE and peer-reviewed sources.
Last updated . See our editorial standards and how we check reviews. This website is run by a USA authorized Protoflow retailer, not by the manufacturer or distributor, PhytoThrive Labs. We make money when you buy through our order links.
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