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Optimum Nutrition Gold Standard 100% Casein Protein Powder vs Vitabiotics Wellman Original

The published reviews of Optimum Nutrition Gold Standard 100% Casein Protein Powder and Vitabiotics Wellman Original, 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

Optimum Nutrition Gold Standard 100% Casein Protein Powder scores 6.6/10 against Vitabiotics Wellman Original's 5.4. The widest gap is evidence for the marketed claim: 7 for Optimum Nutrition Gold Standard 100% Casein Protein Powder, 4 for Vitabiotics Wellman Original.

Pick Optimum Nutrition Gold Standard 100% Casein Protein Powder if…

  • you want the stronger evidence behind what it is sold to do
  • you want a serving that matches the amount used in research
  • tolerability and a well-characterised safety record come first

Pick Vitabiotics Wellman Original if…

  • you want better value against the plain generic version

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 Gold Standard 100% Casein Protein Powder7/10Leads
Vitabiotics Wellman Original4/10

Dose against the studied amount

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

Optimum Nutrition Gold Standard 100% Casein Protein Powder7/10Leads
Vitabiotics Wellman Original5/10

Label transparency

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

Optimum Nutrition Gold Standard 100% Casein Protein Powder6/10Leads
Vitabiotics Wellman Original5/10

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 Gold Standard 100% Casein Protein Powder5/10
Vitabiotics Wellman Original7/10Leads

Safety and tolerability

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

Optimum Nutrition Gold Standard 100% Casein Protein Powder8/10Leads
Vitabiotics Wellman Original6/10

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 Gold Standard 100% Casein Protein PowderNot in the formula
  • Vitabiotics Wellman Original10 µg on current UK listings (5 µg on older ones)In range

Folic acidEvidence A

USPSTF recommended range: 400–800 mcg a day

  • Optimum Nutrition Gold Standard 100% Casein Protein PowderNot in the formula
  • Vitabiotics Wellman OriginalB6 9 mg, B12 9 µg, folic acid 400 µg, thiamin 12 mg and others

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 Gold Standard 100% Casein Protein PowderAbout £36.95–£38.95 for the 924 g tub and £55.79–£64.99 for the 1.8 kg at UK retailers in search listings on 28 September 2026. No per-serving figure: servings not recorded.
  • Vitabiotics Wellman OriginalAbout £4.29–£7.00 for 30 tablets at UK retailers in listings read on 28 September 2026 — roughly 14p–23p a day. 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 Gold Standard 100% Casein Protein Powder

  • Every active ingredient has a stated amount
  • No third-party certification

Vitabiotics Wellman Original

  • Every active ingredient has a 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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