Product Description
Every training session breaks muscle tissue down. That's the point. The adaptation that makes you faster, stronger, and more resilient happens during the repair that follows. But repair requires raw material: amino acids, delivered in the right amounts, in the right window. Without adequate protein after exercise, the breakdown signal your body sent during training doesn't get answered, and the adaptation stalls.
SiS REGO Whey Protein delivers 22g of whey protein concentrate per 30g serving - including 2.8g of L-leucine, all nine essential amino acids, and Vitamins B1, B2, and B6 - in a low-carb formula built specifically for shorter, high-intensity sessions.
Whey Because It Works – Whey is the fastest-digesting complete protein available. When you consume it within the 30–60 minute recovery window after exercise, your muscles absorb amino acids rapidly — stopping the breakdown process and triggering the repair and rebuilding signals your body needs to adapt to training. The 2.8g of L-leucine per serving is particularly meaningful: leucine is the specific amino acid that acts as the "on switch" for muscle protein synthesis, the process of actually building new muscle tissue.
Low Carb by Design – With roughly 2g of carbohydrate per serving, REGO Whey is built for sessions where glycogen depletion isn't the main issue — the kind of training where you're pushing intensity but not duration. This keeps the caloric intake low (~117 kcal per serving) while delivering a full protein hit. If you're coming off a long ride or a multi-hour run, the SiS REGO Rapid Recovery with its full carb-protein ratio is the better call. For everything else, this is your everyday shake.
Informed Sport Certified – Like every SiS product, REGO Whey is independently tested through the Informed Sport program for all compounds on the WADA Banned Substances List. Three flavors — Chocolate, Strawberry, and Vanilla — and mixes clean with water in under a minute.
How to Use SiS REGO Whey Protein
Post-Workout: Add one 30g scoop to 300ml of cold water and shake. Consume within 30–60 minutes after exercise — this is the window when muscle protein synthesis is most responsive to protein intake.
Anytime Protein: Works equally well as a between-meal protein source on high-training days when daily protein targets are hard to hit from food alone.
Stop over-complicating your workout recovery. This is clean, tested whey protein from a brand built for endurance — nothing more, nothing less.
- Gluten free
- Nut free
- Sport Tested: Informed Sport
- 2g
- 21g
- 1g
- 0mg
- 2g
- 0g
Nutrition Facts
45 Servings / Chocolate
Serving Size: 1 Scoop
Serving Per Container: 45
| Amount Per Serving | ||
|---|---|---|
| Calories | 117 | |
| % Daily Value* | ||
| Total Fat 2g | 3% | |
| Saturated Fat 1g | 7% | |
| Trans Fat 0g | ** | |
| Cholesterol 0mg | 0% | |
| Sodium 0mg | 0% | |
| Total Carbohydrate 2g | 1% | |
| Dietary Fiber 0g | 0% | |
| Sugars 1g | ** | |
| Protein 21g | 42% | |
| Caffeine 0mg | ** | |
| L-Leucine 2.8g | ** | |
* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
** Daily Value (DV) not established
Always Happy Promise: Don't like a product? Tell us within 30 days of receipt and we'll make it right and make you happy. Here at The Feed, we want you to love your experience and the sports nutrition products you purchase. If, for any reason, you are not satisfied with your nutrition specific purchase, tell us.
We do not accept returns on food items that have been opened, but we will issue a store credit if you are unsatisfied. In the event of a return, you must first contact us before sending back a return shipment.
Consumable products over $40 receive a 50% store credit. This includes specialty nutrition products such as ketones or supplements/vitamins.
SiS REGO Whey Protein Powder FAQ's
Everything you need to know about SiS REGO Whey Protein Powder.



REGO Whey is designed for shorter, high-intensity sessions where glycogen depletion isn't the primary concern — it delivers a full protein hit at ~2g of carbohydrate and ~117 kcal per serving. REGO Rapid Recovery includes a significant carbohydrate dose alongside the protein, making it the better choice after long rides, multi-hour runs, or any effort where you've genuinely depleted your energy stores. If your session was under 90 minutes and intensity was the driver, REGO Whey is the call. If it was long and hard, go Rapid Recovery.
Protein source matters because not all proteins are absorbed at the same speed or carry the same amino acid profile. Whey is the fastest-digesting complete protein available, and it's naturally high in leucine — the amino acid that acts as the trigger for muscle protein synthesis. Plant proteins can work, but most require larger servings or blending to match the leucine content and absorption rate of whey, making whey the more efficient post-workout option for the recovery window.
REGO Whey uses whey protein concentrate, which retains more natural whey compounds than isolate but also contains a higher level of lactose. Athletes with mild lactose sensitivity often tolerate whey concentrate without issues, particularly in the quantities used here. Those with diagnosed lactose intolerance should approach with caution or consider a whey isolate alternative — the lactose content in concentrate can cause GI discomfort in sensitive individuals.
Leucine is the amino acid that signals your muscles to begin rebuilding after exercise — without it, protein synthesis doesn't start regardless of how much total protein you consume. Research consistently points to approximately 2–3g of leucine as the dose needed to maximally stimulate that process. The 2.8g in REGO Whey sits right in that effective range, which is why leucine content per serving is a more meaningful metric than total protein grams alone.
Yes, though mixing with milk adds carbohydrates, fat, and additional protein on top of the 22g in the powder — which may or may not align with your post-workout goals. For a low-calorie, fast-absorbing recovery hit, water is the cleaner choice. Mixed with milk it becomes a more substantial shake suited to situations where you want extra calories, such as long training days or when it's doubling as a meal replacement.