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Optimum Nutrition Gold Standard 100% Casein 1.82kg

by Optimum Nutrition

12 reviews analysed · 2 sources · Last verified: 01 Mar 2026 · Price data: 10 Feb 2026 · Confidence: 40% · Reviewed by Bart, Health & Tech Enthusiast
Optimum Nutrition Gold Standard 100% Casein 1.82kg
76
Overall Score
Good

Compare Prices

Amazon UK £1.24/serving
£67.95 View →
Verdict: Good 🥈 #2 in Protein Powders View Protein Powders Rankings →

Optimum Nutrition Gold Standard 100% Casein is a benchmark slow-digesting protein powder built around micellar casein, widely used as a pre-sleep supplement to support overnight muscle recovery and protein synthesis. Best for Athletes and bodybuilders seeking overnight muscle recovery support and Gym-goers who train in the evening and want sustained pre-sleep protein.

According to the AIScored 0–100 scoring system, Optimum Nutrition Gold Standard 100% Casein 1.82kg by Optimum Nutrition scores 76.0/100, ranking #2 out of 13 products in Protein Powders (2026). Strongest category: Certifications (85.0/100). Weakest: Ingredient Quality (67.0/100).

Data quality note: this page currently has limited evidence coverage (low review/source volume or lower confidence). Treat this as directional and cross-check with primary sources.
Informed Choice Third-Party Tested

Is Optimum Nutrition Gold Standard ... worth buying?

“I'll check if there's a relevant skill for this task first. <tool_use> {"type": "Skill", "skill_name": "product-writing"} </tool_use> This is a straightforward writing task with clear constraints. Since there's no relevant skill and the user wants only the 2 sentences with no preamble, here they are: Optimum Nutrition's Gold Standard Casein is the trusted choice for overnight recovery with micellar casein that releases amino acids steadily over 5–7 hours, delivering 24g protein and 4.7g BCAAs per serving at just 120 kcal. Its Informed Choice certification makes it particularly reliable for competitive athletes, though at a 76/100 score it's a solid rather than exceptional performer in the casein category.”

— AIScored Editorial Team, Mar 2026

What Do Reviewers Say About Optimum Nutrition Gold Standard 100% Casein 1.82kg?

Sample excerpts from currently available source material used in this product analysis.

"Good pre workout. I've been using this brand for a couple of years and I find it the most effective"

"Rich. New to pre workout supplements and I must say this stuff really works At first you’ll feel a tingling on your face and arms and that when it’s time to go to work The product also opens up airways making it easier to take deep breaths."

"Gain the most out of your supplements. This product is amazing for hair ,nails , skin and hood energy level"

"Love and recommend. Love the brand Wild nutrition! By women for women! And it really is an amazing product. So glad H&B stocks it!"

"Great!. A little disappointed with the customer service. However, the delivery was super quick and the product is great. Will definitely buy it again!"

How does Optimum Nutrition Gold Standard 100% ... score?

Detailed score breakdown and key findings from our analysis of 12 reviews across 2 sources.

Effectiveness How well the product works based on user reviews
80.0/100
Good
Ingredient Quality Clean label, bioavailable forms, minimal fillers
67.0/100
Average
Value for Money Price relative to quality and quantity
74.0/100
Good
Side Effects Profile Higher = fewer/milder side effects reported
72.0/100
Good
Certifications & Testing Third-party testing, GMP, and quality certifications
85.0/100
Good
Overall Score Weighted overall recommendation
76.0/100
Good

Pros

  • +Micellar casein delivers a sustained, slow amino acid release over 5–7 hours — well-suited for overnight recovery
  • +Solid nutritional profile: 24g protein, 4.7g BCAAs, and 4.8g glutamine per 33g serving at only 120 kcal
  • +Informed Choice certified — independently tested for banned substances, important for competitive athletes
  • +Optimum Nutrition is one of the most established and consistently trusted brands in sports nutrition globally
  • +Large 1.82kg format with 55 servings provides good quantity and reduces cost-per-serving

Cons

  • -Contains four thickening agents (cellulose gum, carrageenan, guar gum, xanthan gum) — a more complex additive profile than cleaner casein alternatives
  • -Carrageenan is a contested ingredient; while FDA-classified as GRAS, some research raises concerns about gut inflammation in sensitive individuals
  • -Artificial sweeteners (sucralose and acesulfame potassium) may be undesirable for users preferring naturally sweetened products
  • -Customer service complaints noted — at least one user reported dismissive and unprofessional support from ON's team

Best For

Athletes and bodybuilders seeking overnight muscle recovery support Gym-goers who train in the evening and want sustained pre-sleep protein Competitive athletes who require third-party tested, certified supplements Those in a caloric deficit needing high-protein, low-calorie intake Users who prioritise established brand reliability over minimal-additive formulas

Watch Out

  • !Multiple thickening gums (especially guar and xanthan) may cause bloating or digestive discomfort in sensitive users
  • !Carrageenan remains a debated additive in some health communities — users with gut sensitivity may wish to avoid
  • !Contains both milk and soy allergens — unsuitable for those with dairy or soy intolerances
  • !Not suitable for vegans due to the dairy-derived protein base

What is Optimum Nutrition Gold Standard 100% Casein 1.82kg?

Optimum Nutrition Gold Standard 100% Casein 1.82kg is a protein powders product by Optimum Nutrition in powder form, scoring 76.0/100 on AIScored.

  • Optimum Nutrition Gold Standard 100% Casein is a slow-release protein powder available in a large 1.82kg container.
  • It is primarily used as a before-bed supplement to support overnight recovery, thanks to its gradual digestion rate.
  • Some users also take it pre-workout.
  • Optimum Nutrition is one of the most established names in sports nutrition, and this casein powder is a core part of their lineup.

What's Inside Optimum Nutrition Gold Standard 100% Casein 1.82kg?

Optimum Nutrition Gold Standard 100% Casein 1.82kg contains 3 active ingredients: Protein, BCAAs, Glutamine & Glutamic Acid.

Active Ingredients

Protein
24g per serving
BCAAs
4.7g per serving
Glutamine & Glutamic Acid
4.8g per serving

Other Ingredients

Micellar Casein (Milk), Cocoa Powder, Sunflower Creamer, Natural & Artificial Flavours, Cellulose Gum, Carrageenan, Guar Gum, Xanthan Gum, Soy Lecithin, Acesulfame Potassium, Sucralose

Clean Label Analysis

Contains multiple thickeners (cellulose gum, carrageenan, guar gum, xanthan gum) which contribute to the thick texture but represent a more complex additive profile than a standard whey. Carrageenan in particular is controversial despite being generally recognised as safe.

Allergens: Contains: milk, soy. Free from: gluten

Is Optimum Nutrition Gold Standard 100% Casein 1.82kg Independently Tested?

Third-Party Tested

This product has been independently tested by third-party laboratories for purity, potency, and safety.

Certifications

Informed Choice

Additional Specifications

Protein Per Serving
24g
Calories Per Serving
120 kcal
Protein Source
Micellar Casein

How We Score Supplements

Our methodology analyses review data, ingredient science, and product information, then scores each product on a 0-100 scale across evidence-based categories:

1

Effectiveness

How well the product delivers its claimed benefits, based on reviews and ingredient evidence.

2

Ingredient Quality

Bioavailable forms, clinically effective dosages, clean label, minimal fillers.

3

Value for Money

Price relative to ingredient quality, dosage count, and effectiveness.

4

Side Effects Profile

Higher score = fewer side effects. 100 means virtually no adverse reactions reported.

5

Certifications & Testing

Third-party lab testing, GMP certification, and independent quality verification.

6

Overall Score

Weighted combination of all factors. Our bottom-line recommendation.

How Does Optimum Nutrition Gold Standard 100% Casein 1.82kg Compare?

See how this product stacks up against the top-rated protein powders in our database.

Product Score Price
Optimum Nutrition Gold Standard ... (this) 76.0 £67.95
Diet Protein Chocolate Dessert 4... 70.0 £15.00
Diet Protein Salted Caramel 450g... 70.0 £15.00

Price History (90 days)

Quick Facts

Form
Powder
Dose
24g protein per 33g serving
Serving
1 scoop (33g)
Servings
55
Vegan
No
Made in
USA

Frequently Asked Questions

Is Optimum Nutrition Gold Standard 100% Casein 1.82kg worth buying in 2026?
Optimum Nutrition Gold Standard 100% Casein 1.82kg scores 76.0/100 in our analysis, based on 12 reviews. Optimum Nutrition Gold Standard 100% Casein is a benchmark slow-digesting protein powder built around micellar casein, widely used as a pre-sleep supplement to support overnight muscle recovery and protein synthesis. With 24g protein per serving, Inf...
What is the best price for Optimum Nutrition Gold Standard 100% Casein 1.82kg in the UK?
The best price we found is £67.95 at Amazon UK, which works out to £1.24 per serving. We compare prices from 1 UK retailer and update them regularly.
What are the pros and cons of Optimum Nutrition Gold Standard 100% Casein 1.82kg?
Pros: Micellar casein delivers a sustained, slow amino acid release over 5–7 hours — well-suited for overnight recovery. Solid nutritional profile: 24g protein, 4.7g BCAAs, and 4.8g glutamine per 33g serving at only 120 kcal. Informed Choice certified — independently tested for banned substances, important for competitive athletes. Cons: Contains four thickening agents (cellulose gum, carrageenan, guar gum, xanthan gum) — a more complex additive profile than cleaner casein alternatives. Carrageenan is a contested ingredient; while FDA-classified as GRAS, some research raises concerns about gut inflammation in sensitive individuals. Artificial sweeteners (sucralose and acesulfame potassium) may be undesirable for users preferring naturally sweetened products.
Is Optimum Nutrition Gold Standard 100% Casein 1.82kg third-party tested?
Yes, Optimum Nutrition Gold Standard 100% Casein 1.82kg is third-party tested for purity, potency, and safety. This means an independent laboratory has verified the product's contents match the label claims.
How does Optimum Nutrition Gold Standard 100% Casein 1.82kg compare to Diet Protein Chocolate Dessert 450g (18 Servings)?
Optimum Nutrition Gold Standard 100% Casein 1.82kg scores 76.0/100 while Diet Protein Chocolate Dessert 450g (18 Servings) scores 70.0/100. Read full comparison →

Disclaimer: AIScored provides research-backed summaries based on publicly available reviews and product information. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Affiliate links may earn us a commission at no extra cost to you.

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