The Science

What this page is for

Most brands in this category sell you a feeling. This page is where we put the boring part: what the ingredients we use have actually been studied for, what we are willing to say about them, and what we are not.

Nothing here is medical advice, and nothing here is a promise about what will happen to you.

Why we start with circulation

Blood flow is upstream of most of the things men come to us for — energy through the day, performance in the gym, performance elsewhere, and how quickly you feel recovered. A large part of how well blood moves comes down to nitric oxide, a molecule your body makes that helps blood vessels relax and widen.

Nitric oxide production tends to decline with age. That decline is gradual, which is the honest reason most men never notice it happening — they just notice that something is different at 45 than it was at 25.

The ingredients we care about, and what the research actually shows

L-citrulline

L-citrulline is an amino acid the body converts to L-arginine, which is the raw material for nitric oxide. It has been studied in randomised, placebo-controlled human trials, mostly around exercise performance and blood flow markers. The results are real but modest, and they show up over weeks of daily use rather than after a single dose.

Dietary nitrate (beetroot)

Beetroot is a concentrated source of dietary nitrate, which the body also converts toward nitric oxide. It is one of the better-studied sports-nutrition ingredients there is. Again: measurable, modest, and dependent on taking it consistently.

Everything else

Adaptogens, herbal extracts and mineral blends vary enormously in how well they have been studied. Where the evidence is thin, we will say so on the product page rather than dress it up.

What we do not claim

• We do not claim any product here treats, cures, prevents or diagnoses any condition. Erectile dysfunction, cardiovascular disease, low testosterone and fatigue are medical issues. They belong to your doctor, not to a bottle bought online.
• We do not publish before-and-after numbers, percentage improvements, or clinical results for our own products. We have not run those trials, so we have no right to those numbers.
• We do not use the phrase “clinically proven” about anything we sell.

Where our supplements come from

Our private-label formulas are manufactured in FDA-registered, GMP-certified facilities in the United States. A Certificate of Analysis is available on request for the batch you received — email us and we will send it.

We also resell selected third-party supplements. Where we do, we say who makes it, and we hold those products to the same rule: no claim on our site that the manufacturer cannot back.

How to read any supplement label — ours included

• Look for the dose, not the ingredient. A label that lists ten impressive ingredients without milligrams is telling you it is cheaper than it looks.
• Be sceptical of “proprietary blend”. It is legal, and it is also the standard way to hide how little of the expensive ingredient is in there.
• Check the serving size. A price per bottle means nothing until you know whether a serving is one capsule or four.
• Ask for the COA. Any brand that will not show you a lab result for the batch you bought is asking you to take its word for it.

Safety, and who should not take these

Ingredients that support blood flow can interact with medication that does the same thing. Talk to your physician before you start, and do not start without that conversation, if you:

• take nitrates (including nitroglycerin), blood pressure medication, or blood thinners;
• take medication for erectile dysfunction;
• have a heart condition, or have had a cardiac event;
• are scheduled for surgery within the next two weeks.

Not for use by anyone under 18. If you are pregnant or nursing, do not use these products. Stop use and speak to a doctor if you have an adverse reaction.

How long before anything happens

The ingredients above were studied over weeks of consistent daily use. If you take a product for four days and feel nothing, that is the expected result, not a failure of the product. If you take one for eight weeks and still feel nothing, it may simply not be doing anything for you — and we would rather you stopped than kept buying it.

†These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.