read this before your first packet

how to drink it.

half a packet in 12 to 16 oz of water is a serving. one packet a day is the limit. here is why those are the numbers, and exactly who should ask a doctor first.

½ packetone serving
12–16 ozof water
1 packeta day, maximum

stir half a packet into a large glass of water, 12 to 16 oz. that is one serving, and a packet makes two. it is the dose the per-serving figures describe.

why half a packet.

because a whole packet is a real dose. a classic packet holds 420 mg of magnesium, which is a full day’s recommended allowance for a man¹ and above the 350 mg tolerable upper level for magnesium from supplements, the level set to avoid loose stools in otherwise healthy adults.¹² it also holds about 940 mg of potassium, a fifth of the daily value. half a packet is a serving so that a serving sits comfortably inside those numbers.

the whole packet in one bottle is a bigger dose, a hard-sweat dose. it is fine for most healthy people on a hot day, and it is still 20% of the daily value for potassium. but it is a choice to make on purpose, which is why we print both figures on the packet.

why 12 to 16 oz.

concentration. the science behind oral rehydration showed that a lighter, balanced solution is absorbed better and sits better than a heavy one³, and the sodium-glucose transporter that does the absorbing works best when neither ingredient is crowded.⁴ half a packet in 12 to 16 oz lands in the range that tastes like a drink and behaves like one. in less water it is stronger than it needs to be and, frankly, saltier than you want.

cold or room temperature does not matter to absorption. stir or shake until it is clear; honey powder takes a few seconds longer than the minerals.

not recommended

a full packet in one water bottle.

people do it. the whole packet is a double dose in one drink, and we would rather you knew exactly what that means before you decide, so here are the risks first and the arithmetic second.

the risks, in order of how likely they are

your stomach. a whole classic packet is about 420 mg of magnesium in one go, and squared² is about 840 mg. the tolerable upper level for magnesium from supplements is 350 mg a day, and it exists for exactly this reason: above it, unabsorbed magnesium pulls water into the gut and loose stools follow, faster on an empty stomach.¹² this is the most common way a full packet goes wrong. it is not dangerous for a healthy adult; it is unpleasant and it defeats the purpose, because what you lose out the other end is water and electrolytes.
it is a strong solution. a full packet in 12 to 16 oz is roughly twice the strength the packet was built for. the rehydration research is clear that lighter, balanced solutions are absorbed better and sit better than heavy ones; concentrated drinks empty from the stomach more slowly and can cause cramping or nausea, especially during exercise.³ if you do use a whole packet, the water matters more, not less: 24 to 32 oz, not 12.
potassium. about 940 mg at once, a fifth of the daily value, in both formulas. healthy kidneys handle that without drama. the people who should not do this at all are the ones on the who-should-check list below: anyone with kidney disease, heart failure or adrenal insufficiency, or taking an ace inhibitor, an arb or a potassium-sparing diuretic, because those conditions and medicines raise blood potassium and a bolus dose is the wrong way to find out.⁵ for them, a full packet is not “not recommended.” it is off the table until a doctor says otherwise.
sodium, mainly for squared². a full squared² packet is about 1,150 mg of sodium, half the daily chronic-disease-risk-reduction level in one bottle.⁶ on a hard, hot day that can be exactly what you lost in an hour of sweat.⁷ on a desk day it is just a lot of salt, and anyone on a sodium-restricted diet should not be doing it at all.
caffeine, squared² only. 75 mg in one drink is about a modest cup of coffee, well inside the usual 400 mg a day guidance for healthy adults, but it is a single dose rather than the two the packet was designed as.⁸
a second packet the same day. this is the line we will not soften. a full packet is already the day’s maximum. two is a full day of magnesium twice over and a real potassium load, and there is nothing to gain from it.

the formulation, whole packet

these are the whole-packet figures, the same ones printed on the packet under “per packet.” a serving is half of each.

a full packet in one bottle	classic	squared²	against the reference
sodium	25% DV · ~575 mg	50% DV · ~1,150 mg	daily value 2,300 mg⁹
magnesium	100% DV · ~420 mg	200% DV · ~840 mg	supplemental upper level 350 mg/day¹
potassium	20% DV · ~940 mg	20% DV · ~940 mg	daily value 4,700 mg⁹
vitamin c	1000% DV · 1,000 mg	1000% DV · 1,000 mg	upper level 2,000 mg/day; absorption falls off above ~200 mg¹⁰¹¹
sugar (honey)	15 g · 60 cal	25 g · 100 cal	the glucose that runs the transporter⁴
caffeine	0 mg	75 mg	up to 400 mg/day for healthy adults⁸
water it was built for	2 × 12–16 oz	2 × 12–16 oz	if you must: 24–32 oz, drunk over an hour

if you are going to do it anyway: be a healthy adult with none of the conditions or medicines above; do it on a genuinely hard, hot day, not a desk day; use the most water, 24 to 32 oz, and drink it over an hour with food in you rather than in one go; and count it as the whole day. that is the honest version of “a hard-sweat dose.” the recommended version is still half a packet, twice.

why one packet a day is the limit.

not a suggestion, a limit, and here is the arithmetic. a whole classic packet is already a full day’s magnesium and a real dose of potassium; a whole squared² packet is 840 mg of magnesium and half the day’s sodium reference amount.⁹ there is nothing to gain from a second one and something to lose: extra supplemental magnesium is what the upper level exists for², and potassium is cleared by the kidneys at a rate that is easy to respect and unwise to test.¹²

if you are sweating hard enough for long enough that one packet does not feel like enough, the honest answer is food and a sodium-containing drink you drink to thirst, not a second packet.⁷¹³

when in the day.

classic, any time. many people like a serving with breakfast and another mid-afternoon.
squared² carries 75 mg of caffeine per packet, about 37 mg a serving. earlier is better; caffeine’s half-life in most adults is several hours.¹⁴
around exercise, a serving in the hour before and one after is a reasonable pattern for a long, hot session; for an ordinary workout, one is plenty.¹⁵
drink to thirst. a packet is not a reason to force fluids. it is a reason the fluids you drink stay with you.¹³

who should check with a doctor first.

this is an electrolyte product, so it is a real dose of minerals rather than a sprinkle. that is the whole point of it, and it is also the reason a few people should ask first. the concern is almost entirely potassium: the kidneys hold blood potassium in a narrow band, and some conditions and some very common medicines make that harder.⁵

talk to your doctor or pharmacist before using salty smiles if you have kidney disease, heart failure, or adrenal insufficiency, or if you take a potassium-sparing diuretic (such as spironolactone, eplerenone, amiloride or triamterene), an ace inhibitor (the “-pril” blood-pressure medicines) or an arb (the “-sartans”). these can all raise blood potassium.⁵

the same goes for a sodium-restricted diet, since a packet is a quarter to a half of the daily sodium reference amount; a history of kidney stones, because potassium citrate changes urine chemistry in ways that help some stone types and not others¹⁶; and if you are pregnant or nursing, when the sensible default for any supplement is to ask.

not intended for children. the doses are sized for adults. keep to one packet a day.

we are a drink mix company, not your clinician. the studies on this site are linked so that you and your doctor can read them, and that conversation is worth five minutes.

a note on taste and settling.

salty smiles is salty. it is in the name, and the sodium is the point; if a serving tastes like a sports drink from a vending machine, it is not doing the job those studies describe.¹⁷ if it is too strong for you, use the full 16 oz, or start with a third of a packet and work up. real fruit powder can settle in the glass over ten minutes; swirl and carry on.

build your order next: when to use it

studies & sources on this page

Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. The National Academies Press, 1997.
NIH Office of Dietary Supplements. Magnesium: fact sheet for health professionals. National Institutes of Health.
Hahn S, Kim Y, Garner P. Reduced osmolarity oral rehydration solution for treating dehydration due to diarrhoea in children: systematic review. BMJ, 2001; 323(7304): 81–85.
Wright EM, Loo DDF, Hirayama BA. Biology of human sodium glucose transporters. Physiological Reviews, 2011; 91(2): 733–794.
Palmer BF. Managing hyperkalemia caused by inhibitors of the renin–angiotensin–aldosterone system. New England Journal of Medicine, 2004; 351(6): 585–592.
National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Sodium and Potassium. The National Academies Press, 2019.
Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. American College of Sports Medicine position stand: exercise and fluid replacement. Medicine & Science in Sports & Exercise, 2007; 39(2): 377–390.
U.S. Food & Drug Administration. Spilling the beans: how much caffeine is too much?. FDA consumer update.
U.S. Food & Drug Administration. Daily Value on the Nutrition and Supplement Facts labels. FDA, updated for the 2016 label rule.
Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. The National Academies Press, 2000.
Levine M, Conry-Cantilena C, Wang Y, et al.. Vitamin C pharmacokinetics in healthy volunteers: evidence for a recommended dietary allowance. Proceedings of the National Academy of Sciences, 1996; 93(8): 3704–3709.
NIH Office of Dietary Supplements. Potassium: fact sheet for health professionals. National Institutes of Health.
Hew-Butler T, Rosner MH, Fowkes-Godek S, et al.. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference. Clinical Journal of Sport Medicine, 2015; 25(4): 303–320.
EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific opinion on the safety of caffeine. EFSA Journal, 2015; 13(5): 4102.
Kenefick RW, Cheuvront SN. Hydration for recreational sport and physical activity. Nutrition Reviews, 2012; 70(Suppl 2): S137–S142.
Zuckerman JM, Assimos DG. Hypocitraturia: pathophysiology and medical management. Reviews in Urology, 2009; 11(3): 134–144.
Shirreffs SM, Taylor AJ, Leiper JB, Maughan RJ. Post-exercise rehydration in man: effects of volume consumed and drink sodium content. Medicine & Science in Sports & Exercise, 1996; 28(10): 1260–1271.

every study above is linked to the original record. the full library is on the studies page.

*these statements have not been evaluated by the food and drug administration. this product is not intended to diagnose, treat, cure, or prevent any disease. the deep dive is background reading, not medical advice — the studies are linked so you can read them yourself, and your doctor or pharmacist knows your situation. we don’t.