Sports Research Whey Protein Isolate - Sports Nutrition Protein Powder 25g per Serving - 5lb Bag Whey Protein - Vanilla Flavor - Bulk Protein Powder, 56 Servings
$1.12/serving
Price verified Apr 22, 2026
Not evaluated by the FDA · Individual results may vary · Consult a healthcare provider before use
Our verdict
25g whey protein isolate + 6.9g BCAAs + 1000mg L-Leucine per serving of Whey Protein Isolate (US-sourced, 25g per serving) with 1000mg added L-Leucine and Vitamin D per powder from…
Why we recommend this
For non-drug-tested athletes who prioritize US-sourced whey with a cleaner additive profile (no xanthan gum, no artificial sweeteners) and appreciate the leucine fortification, Sports Research Whey Isolate delivers on its technical promises. The formula itself is sound; the 3.8-star rating reflects taste preference variation rather than a product safety or quality failure. Buyers who enjoy natural vanilla flavor and clean ingredient decks are likely to rate this higher than the average suggests.
Check for interactions
Already taking other supplements or prescription medications? Add them below to check for documented interactions, severity, and clinical guidance.
Our database currently documents 137+ supplement and drug-category interaction pairs. Combinations not flagged here may still interact — always consult your healthcare provider before combining supplements, especially with prescription medications.
What to watch out for
The 3.8-star rating is the primary concern — mixed reviews suggest the natural vanilla flavor may polarize users, and some batches reportedly have mixability inconsistencies. The lack of an Informed Sport or NSF Sport certification means drug-tested athletes cannot confidently use this product. At $1.61 per serving, competitors with similar protein profiles and higher ratings offer better value.
Dose & form
- Serving
- 25g whey protein isolate + 6.9g BCAAs + 1000mg L-Leucine per serving
- Form
- Powder
- Clinical range
- 20-40g per serving, 1.6-2.2g/kg/day total protein for athletes
- Dose adequacy
- Therapeutic
- Supply
- 80 servings · $1.12/serving
- UPC
- 023249091844
Who it's best for
Fitness-focused adults who want a clean US-sourced whey isolate with enhanced leucine and vitamin D without artificial sweeteners or xanthan gum
Who should skip it
Budget shoppers or those sensitive to price per serving — at $89.95 for 56 servings, the cost-per-scoop is above the category average
Pros
- 1000mg added L-Leucine per serving enhances muscle protein synthesis signaling beyond what whey alone provides
- US-sourced whey isolate with under 1g sugar and 150 calories — a lean, clean macro profile for cut or maintenance phases
- No xanthan gum or artificial sweeteners — naturally flavored vanilla with minimal additives for a protein powder
- Versatile formulation: designed for shakes, smoothies, baking, and coffee creamer applications without clumping
Cons
- 3.8-star average from 540 reviews is below the category quality threshold, suggesting mixed reception on taste or mixability
- $89.95 for 56 servings equates to $1.61/serving — premium pricing that may not be justified given the below-average rating
- No third-party certification (Informed Sport, NSF for Sport) visible on the listing — a gap for drug-tested athletes
What customers say
3.8★ across 540 Amazon reviews. The most common questions from shoppers: re any potential interactions with medications, re any side effects from long-term use, and cause any digestive issues or side effects. Full answers in the FAQ below.
Frequently Asked Questions
What is the clinical dose for Whey Protein Isolate (US-sourced, 25g per serving) with 1000mg added L-Leucine and Vitamin D?
What is the clinical dose for Whey Protein Isolate (US-sourced, 25g per serving) with 1000mg added L-Leucine and Vitamin D?
Clinical trials typically use 20-40g per serving, 1.6-2.2g/kg/day total protein for athletes. Sports Research Whey Protein Isolate Powder — Vanilla delivers 25g whey protein isolate + 6.9g BCAAs + 1000mg L-Leucine per serving, which we classify as Therapeutic relative to that range.
How does Sports Research Whey Protein Isolate Powder — Vanilla compare to similar Powder?
How does Sports Research Whey Protein Isolate Powder — Vanilla compare to similar Powder?
See the "Also consider" section below for two alternatives. Choose based on form preference (Powder vs alternatives), dose adequacy, and third-party testing.
Is Sports Research Whey Protein Isolate Powder — Vanilla third-party tested?
Is Sports Research Whey Protein Isolate Powder — Vanilla third-party tested?
Yes — Third-Party Tested (cGMP, Non-GMO Verified). Third-party testing verifies ingredient identity and label accuracy.
Is Sports Research Whey Protein Isolate Powder — Vanilla in stock?
Is Sports Research Whey Protein Isolate Powder — Vanilla in stock?
Current availability: OutOfStock. Stock status reflects the latest Amazon refresh — check the Amazon link for real-time status.
Are there any potential interactions with medications?
Are there any potential interactions with medications?
Whey protein does not have clinically significant interactions with most medications at typical supplement doses. Individuals with kidney disease should consult a physician before high-protein supplementation, as elevated protein intake can increase renal filtration load. Those taking tetracycline or quinolone antibiotics should separate their protein shake by 2+ hours, as high calcium content can reduce antibiotic absorption.
Are there any side effects from long-term use?
Are there any side effects from long-term use?
Whey protein isolate is one of the most studied dietary supplements with an excellent long-term safety profile in healthy adults at doses up to 40–60g daily. Some individuals with lactose sensitivity may experience mild GI discomfort, though isolate has significantly lower lactose than concentrate. Excessive total protein intake (above 3g/kg body weight) over months may place strain on kidney function in susceptible individuals.
Does it cause any digestive issues or side effects?
Does it cause any digestive issues or side effects?
Whey isolate is lower in lactose than whey concentrate, making it better tolerated by most lactose-sensitive users. Some users experience bloating or mild cramping if consuming very large servings (50g+) rapidly. The absence of xanthan gum in this formula — a common thickener that can cause GI distress — is a deliberate design choice that may improve digestive tolerance for sensitive individuals.
Can it be taken with other supplements or vitamins?
Can it be taken with other supplements or vitamins?
Yes — whey protein stacks seamlessly with creatine, BCAAs, pre-workouts, omega-3s, and vitamins. The added 1000mg L-Leucine means you do not need to add a separate leucine supplement when using this product. Mixing with casein protein before bed is a common practice to cover both fast-release (whey) and slow-release (casein) protein windows.
Are there any specific instructions for taking it safely?
Are there any specific instructions for taking it safely?
Mix one scoop with 8–10 oz of water, milk, or milk alternative in a shaker bottle. Consume within 30–60 minutes post-workout for optimal muscle protein synthesis. Do not exceed 2 scoops (50g protein) per serving, as larger single doses provide diminishing MPS returns. Stay adequately hydrated throughout the day when using a high-protein supplement regimen.
How long until benefits are typically experienced?
How long until benefits are typically experienced?
Acute muscle protein synthesis elevation occurs within 60–90 minutes of consuming whey protein post-workout. Cumulative lean muscle gains from consistent whey supplementation alongside resistance training are typically measurable within 6–12 weeks of a structured program. The 1000mg added leucine is specifically included to optimize the acute MPS response per serving.
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