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Optimum Nutrition Opti-Men vs Supergut Prebiotic Shakes

Short answer: Supergut Prebiotic Shakes is the better pick on our scores (5.2 vs 5.0 out of 10).

The published reviews of Optimum Nutrition Opti-Men and Supergut Prebiotic Shakes, lined up: the five scores, what one serving delivers against the studied dose, the real cost per serving and what each label leaves out. Figures as of 28 September 2026.

The short answer

Supergut Prebiotic Shakes scores 5.2/10 against Optimum Nutrition Opti-Men's 5.0. The widest gap is value against the generic equivalent: 3 for Optimum Nutrition Opti-Men, 5 for Supergut Prebiotic Shakes.

Pick Optimum Nutrition Opti-Men if…

  • you want every amount on the label disclosed
  • tolerability and a well-characterised safety record come first

Pick Supergut Prebiotic Shakes if…

  • you want better value against the plain generic version
  • you want a serving that matches the amount used in research

Criterion by criterion

The five criteria every review is scored on, published on the grading page. The overall score is their average.

Evidence for the marketed claim

How strong the research is for what the product is actually sold to do — not for the ingredient in general.

Optimum Nutrition Opti-Men4/10
Supergut Prebiotic Shakes4/10

Dose against the studied amount

Whether one serving delivers the amount used in the research behind the claim.

Optimum Nutrition Opti-Men5/10
Supergut Prebiotic Shakes6/10Leads

Label transparency

Whether the Supplement Facts panel is published in readable text and every active amount is disclosed.

Optimum Nutrition Opti-Men5/10Leads
Supergut Prebiotic Shakes4/10

Value against the generic equivalent

Cost per gram or per dose of the active ingredient, compared with the plainest version of the same thing.

Optimum Nutrition Opti-Men3/10
Supergut Prebiotic Shakes5/10Leads

Safety and tolerability

Known risks and interactions, how well characterised they are, and whether the label warns about them.

Optimum Nutrition Opti-Men8/10Leads
Supergut Prebiotic Shakes7/10

Dose against the studied amount

What one labelled serving delivers, placed against the range on each ingredient’s evidence page. Where a label gives no figure, there is nothing to place, and that is the finding.

Vitamin DEvidence A

NHS daily amount to adult upper limit: 10–100 mcg a day

  • Optimum Nutrition Opti-Men10 µg (200% NRV)In range
  • Supergut Prebiotic ShakesNot in the formula

Folic acidEvidence A

USPSTF recommended range: 400–800 mcg a day

  • Optimum Nutrition Opti-MenB6 5.4 mg, B12 9.0 µg, niacin 54 mg, folic acid 90 µg and others at 45–386% NRV
  • Supergut Prebiotic ShakesNot in the formula

Green tea extractEvidence C

No single studied range in label units, so amounts are shown but not placed.

  • Optimum Nutrition Opti-MenNot disclosed on the listings we could readUndisclosed
  • Supergut Prebiotic ShakesNot in the formula

Rebaudioside A (stevia)Evidence D

No single studied range in label units, so amounts are shown but not placed.

  • Optimum Nutrition Opti-MenNot in the formula
  • Supergut Prebiotic ShakesNot stated

What it actually costs

Price divided by labelled servings, from a dated listing. A serving is whatever the label calls one, which is why the studied-dose row matters more than the headline figure.

  • Optimum Nutrition Opti-MenAbout £14.95–£19.99 for 90 tablets at UK retailers in search listings on 28 September 2026 — roughly 50p–67p a day. No per-serving figure: servings not recorded.
  • Supergut Prebiotic Shakes$14.99 for 8 servings on Amazon.com with an on-page coupon, against a usual listed price of about $30, in listings read on 28 September 2026. We could not confirm a current price for the 14-serving bag. No per-serving figure: servings not recorded.

Label checks

What each label discloses, and what it leaves out. Read from the reviews, not from the marketing.

Optimum Nutrition Opti-Men

  • 1 of 6 listed ingredients have no stated amount
  • No third-party certification

Supergut Prebiotic Shakes

  • 1 of 4 listed ingredients have no stated amount
  • No third-party certification

How this comparison is built

  • Scores are the ones already published in each review. Nothing is re-scored for the comparison, and a product leads a criterion only when it outscores the rest.
  • Doses are read from the label rows in each review and placed against the studied range on the matching ingredient page. A figure that is not printed is never estimated.
  • Costs use a dated retailer price divided by labelled servings. Prices in different currencies are never ranked against each other.
  • Only products in the same category, or ones a review names as an alternative, can be compared. Commission never changes what appears here.

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