SOS Electrolyte Review

Overall Score

Last Updated October 31, 2021
  • Effectiveness 90% 90%
  • Flavor 65% 65%
  • Ingredients 100% 100%

Key Takeaways


Science-backed Formula that Includes a Variety of Electrolytes and Sugar

Backed by independent university studies that studied the effects of SOS including Coventry University in 2016.


Mild and Light Citrus Taste

Ideal for people with sensitive stomachs.



Contains a Small Amount of Sugar

Only 3g per serving: enough to aid with hydration but not a major source of calories.

Low sugar

Low calorie


Interested in Buying?


SOS was started by two British athletes seeking a low sugar electrolyte supplement for performance athletes. The formula is modeled after the World Health Organization’s Oral Rehydration Solution, which is the gold standard for rehydration. SOS is the only mix we’ve tested that actually worked with independent researchers to study the effectiveness of their product. The results, which are posted on their website, indicate that SOS is more effective than many of the other leading electrolyte brands. The company’s attention to science based product development and elite athletics credentials are compelling but that is not enough to blindly trust them. Our reviewers tested their product in a number of environments and conditions to see if we could really rely on it, especially during high intensity athletic pursuits. 

Hydration Review came away from extensive testing with a positive impression of the SOS product. Its effectiveness was validated in many different environments: gyms, the wilderness, exercise classes and the home offices. The packaging was also advertised as being compostable which some of our more environmentally conscious reviewers appreciated. After performing dozens of reviews, electrolyte brands can start to blend together, but SOS stands out as a special product. 


Our review team was not aware of the SOS company background prior to testing and as a result could go in with an open mind. Reviews were positive when the product was used during or after physical activity and heavy sweating. Reviewers reported quicker recoveries after long days of hiking and mid-summer outdoor workouts. The mixer accompanied several reviewers on an overnight backpacking trip in the Tetons where temperatures crested 90 degrees, despite being above 10,000 feet. The combination of heat and elevation can be draining, but constant hydration with SOS helped the reviewers keep going and reach their destination. 

Using SOS on low activity days did not produce negative results but the effects were less profound. The best use case outside of exercise is undoubtedly hangover treatment. SOS lived up to its name for reviewers who used it as a hangover aid. Several users noted they instinctively reached for this product when their hangover symptoms had them calling for an “SOS.” The low salt and sugar contents were just what they needed to get their bodies back on track. One packet was enough to help remove the fog and fatigue associated with the alcohol from the night before.

“I went for SOS the morning after a night of drinking since I noticed they advertised this use case on the packaging. I took it first thing in the morning after waking up feeling headachy and pretty sluggish overall… Within 30 minutes I felt noticeably better and had the strength to get up and start my day.” 

SOS also was tested independently at Coventry University and Auckland Institute of Technology, where they compared its effectiveness to rival products. It’s no surprise to our reviewers that the findings indicate SOS was a more effective rehydration tool than water alone and also beat the performance of all other brands tested. 


SOS offers six flavors: Lemon Lime, Berry, Coconut, Watermelon, Mango and Fruit Punch. The HydrationReview team has only tried Lemon Lime and had a slightly positive take. The flavor is subtler than many other brands which could be related to the lower sugar content. It was preferred by reviewers with sensitive stomachs but overall reactions were middle of the road, with no extreme like or dislike of the flavor.


SOS paid careful attention to ingredient selection during product development and excluded anything we would consider harmful or unhealthy. Their formula closely resembles the WHO Oral Rehydration Solution (ORS) which is the most studied rehydration medicine. Unlike some other brands that use a formula related to ORS, SOS also includes zinc. According to the WHO, Zinc deficiency inhibits the absorption of water. Zinc deficiency is not a huge concern in developed countries unlike malnourished populations but it could help with general immunity. 

Interested in Buying?

Go Deeper

Related Reviews

Acli-Mate Mountain Sport Drink Review

Acli-Mate Mountain Sport Drink Review

A specialized electrolyte mix that is a great companion for any high elevation exertion.

UCAN Electrolyte Review

UCAN Electrolyte Review

Electrolytes formulated for athletic training by a team of scientists and professional athletes.

Nectar Electrolyte Review

Nectar Electrolyte Review

An all-natural electrolyte best suited for low activity days.

Stay Updated (and Hydrated)


Share This