S!CAPS (Buffer/Electrolyte Capsules)

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Developed in 1995 by scientist and ultramarathoner Karl King, SUCCEED! Electrolyte Caps have become The Gold Standard for Electrolyte Replacement™.

S! Caps are 100% electrolytes. Beware of imitations that use ineffective, non-electrolyte fillers such as sugars or the carbohydrate maltodextrin.

  • Alleviation of cramping
  • Buffers to help stabilize the stomach
  • Protection against potentially fatal hyponatremia
  • Sodium and potassium in effective amounts
  • Phosphate and citrate for energy production
  • S! Caps is the ONLY electrolyte product that delivers the correct ratio of electrolytes (cations and anions)
  • Vege caps for vegetarians!

The First Aid patrol at the Western States 100 found me along the trail at 52 miles suffering from leg cramps. They were kind enough to share their Succeed S Caps (half their stash) to get me going and get me through to the finish. I recovered faster than I thought I would. I have used S Caps in all of my 100's (and ultras) since then.

Mike Gleman

Check out the Trail Runner Nation podcast on electrolytes!

Electrolyte supplementation is primarily about sodium replacement, and S! Caps deliver more for your money than any other supplement. Don't waste your money on imitations that supply less than half the sodium of S! Caps and will let you down when the heat is on. Of course, others have tried to imitate this formulation, but have failed to deliver a product as good as S! Caps.

Nutrition Facts labels normally list sodium content as the element, but some products have misleading labels that express the sodium content as sodium chloride (table salt). This leads the unsuspecting reader to think that they are getting more sodium because the numbers are large.

The S! Caps label lists sodium as the element, 341 mg per capsule. If you want to compare to other products that list the sodium as sodium chloride, S! Caps supply 867 mg of sodium as sodium chloride.

We encourage you to read labels so that you understand why S! Caps are the superior electrolyte supplement. See our Integrated Solution page to see why we don't load up our formulations with the “kitchen sink” list of ingredients that are present in quantities too small to have any real effect.

S! Caps provide all of the major blood plasma electrolytes that other formulations are missing [ sodium, potassium, chloride, bicarbonate, and phosphate ]. S! Caps contain ONLY electrolytes with no fillers or vitamins that aren't really needed in an electrolyte formulation.

What about magnesium? “Magnesium is another intracellular ion that, like potassium, is lost in sweat and urine during exercise. But the losses are trivial. There is no published evidence showing that magnesium deficiency is either common amongst the physically active, or that magnesium supplementation can either increase the intracellular magnesium stores, or enhance performance.” Dr. Timothy Noakes Sports Nutrition: Fluid, Electrolytes, and Minerals (Report from the World Forum on Physical Activity and Sport, Quebec City, Canada, 1995.)

S! Caps give you the electrolytes you need without unneeded stuff taking up room in the capsule.

Heavy sweating during athletic performance lasting for many hours can cause loss of critical electrolytes from blood plasma. Modera te loss of electrolytes can degrade performance, while heavy losses can lead to hyponatremia (low blood sodium) that can cause collapse and death in extreme cases. Sports drinks can provide adequate sodium input for a few hours of exercise, but are insufficient over longer periods. Energy bars and gels are low in sodium and should be supplemented with electrolytes. SUCCEED! BUFFER/ELECTROLYTE CAPS provide electrolytes that are commonly found in blood plasma (sodium, potassium, chloride, bicarbonate, phosphate), in the proper proportions for hours of exercise. When taken with sufficient water, they help the body maintain good hydration status, which allows performance at a high level. As we claimed back in 1995 before others had even thought about appropriate electrolyte replacement in endurance events: they also contain a chemical buffering system that neutralizes the acids formed during heavy exercise. Neutralization of excess acid will help performance and reduce the nausea associated with exercise in the heat. Maintenance of proper electrolyte levels will reduce swelling of hands and feet after many hours of exercise, and that will reduce “hot spots” and blisters on the feet. The buffers in S! Caps also help soothe the stomach.



Endurance athletes know that dehydration and electrolyte imbalance can lead to big problems during an event, but recent studies show that dehydration can also lead to migraines. Fortunately for some people, taking an S! Cap with a glass of water can prevent a migraine that is coming on, or stop one that has started. Instead of taking medications for migraine, some people can simply take an S! Cap with water to get relief – no drugs needed, just your body’s natural electrolytes as supplied by S! Caps.

Serving size: 1 capsule Servings per container: 100
NutrientAmount per capsule%RDA
Sodium 341 mg 13.6
Potassium 21 mg 0.5

* No RDA established at this time.

52 Reviews

Alan Stuckert May 1st 2024


I learned the hard way, don't run out. I have used for 3 years. Never ever felt dead on my saddle during a long ride. Forgot to reorder in time for this past weekend MS 150. I bonked bad on Day 2 of the ride. First SAG ever. So glad I am now resupplied.

Phil Apr 9th 2024

Put simply: these work

I've used Succeed S-Caps for years, and they make all the difference on long training runs, marathons and ultras. They are a critical part of my hydration strategy, enabling me to maintain my electrolyte balance even when I'm sweating a lot.

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