Our methodology

How we test and review supplements

Every Mettle Health Review verdict follows the same playbook: buy the product ourselves, live with it, score it against fixed criteria, and read widely before we publish. This page explains exactly how we work and how we stay independent.

Who we are

Mettle Health Review is an independent review publication focused on men's health, vitality and performance supplements. We are published by Mettle Media Group LLC, based in Charlotte, North Carolina, and we have been reviewing supplements since 2021. We are not a manufacturer, a pharmacy, or a brand's marketing arm. Our only job is to help a reader decide whether a given product is worth their money before they buy it.

That independence is the whole point. When we review a product like Spartamax, we are a third party looking in, not the company selling it. We say so plainly throughout the site, and we keep the way we make money separate from the way we score (more on that below).

Meet the reviewer

Our Spartamax review was led and signed off by Garrett Pruitt, MS, a Certified Sports Nutritionist (CISSN) who has spent more than a decade working with active adults on nutrition and supplementation. Garrett reviews the men's-vitality category for us, checks that ingredient claims are described accurately and within compliance, and makes sure our tone stays balanced rather than promotional. Reviews are drafted by our test team and then fact-checked and approved by Garrett before publishing.

To be clear about what this is and is not: our reviewer provides editorial expertise, not medical advice. Nothing on this site is a substitute for talking to your own doctor.

How we test a product

We buy the product at full retail price through the normal customer checkout, the same way you would. We do not accept free units from brands in exchange for coverage, because that creates an obvious bias. For Spartamax, that meant ordering from the official website and using the standard formula.

At least one team member then uses the product daily for a real trial window, typically eight to nine weeks for a supplement that is meant to build up over time. We keep a simple daily log covering the things buyers actually care about: energy, physical performance, sleep, mood and, for this category, libido. We note onset, what changed, what did not, and any tolerability issues. We treat our own experience as informative context, not as clinical proof, and we say so in the review.

How we score

We rate every product out of 5 on eight weighted criteria. The weights reflect what matters most to a buyer: real-world effectiveness and whether people stick with it count for more than nice-to-haves. The weighted average becomes our editorial score (Spartamax earned a 4.2).

How we use user reviews

Alongside our own testing, we aggregate user feedback to capture a far bigger sample than one team can produce. For Spartamax we compiled 1,247 reviews from purchase records and public sources, then looked at the distribution of ratings, recurring themes (both positive and negative), how long people waited for results, and basic demographics. We deliberately surface the critical reviews, not just the happy ones, because a page with no complaints is not a real review.

An honest note on these figures: they are an editorial aggregation meant to show the shape of customer sentiment. They are not a certified or independently audited dataset, and individual results always vary.

Editorial independence and how we are funded

Mettle Health Review is reader-supported. Some links on our reviews go to a brand's official website, and if you buy through one of them we may earn a commission, at no extra cost to you. That is how we pay for the products we buy and the time we spend testing.

Here is our firm rule: commissions never influence our scores, our ranking or what we write. We score the product first and add the links second. We will happily publish a low score on a product we earn commission from, and our cons sections prove it. For the full details, see our affiliate disclosure.

Corrections and contact

If a price, ingredient or detail changes, or if you spot something that needs fixing, email us at [email protected] and we will update the review. We date every page so you can see when it was last checked.