Electrolytes Before Bed: What Sodium Does Overnight, and Will It Make You Wake to Wee?

By Roy, founder Last updated 14/10/2026

Updated 14 October 2026

You go about eight hours without a drink, and sodium is the mineral that helps your body hold on to the fluid it has. In lab trials, drinks with more sodium were retained better than drinks with less. What gets people up to wee in the night is mostly how much they drink close to bed, plus alcohol and caffeine, so a small glass with sodium 30 to 60 minutes before bed is a different thing from a big evening drink.

This page covers what sodium does overnight, what really drives night-time toilet trips, how 1,000mg compares with an Australian day's intake, and who should check with a GP first.

Why would you have sodium before bed?

Because overnight is the longest stretch of the day without a drink. You lose some fluid through your breath and through sweat while you sleep, and you can't top up until morning. Plain water before bed helps, but sodium is what helps the body hold on to the fluid it takes in.

That is the idea behind an electrolyte layer in a nightly drink: so eight hours without water does not wake you dried out and needing to get up. We cover the whole overnight picture in the electrolytes article and the hydration and sleep article. Here is the research behind the sodium part.

What does sodium do to the fluid in your body?

Sodium is the main positively charged mineral in the fluid around your cells, and it has an essential role in keeping the volume of that fluid steady. That is how Australia's nutrient reference values describe it (NHMRC). The Heart Foundation puts it more plainly: sodium helps with nerve signals, muscle movement and fluid balance (Heart Foundation).

Two sets of trials look at what that means for a drink:

• Maughan et al, 2019. Healthy young men who were not dehydrated drank 1 litre of beverages with different amounts of sodium. Over the next 4 hours they passed less urine, and kept more fluid, on the drinks with 27 and 52 mmol/L of sodium (about 620 and 1,200mg per litre) than on the drinks with 7 and 15 mmol/L. Caffeine made no difference (Maughan et al).
• Shirreffs et al, 1996. Men who had lost fluid through exercise drank different volumes of drinks with low and higher sodium. The finding was that unless the sodium content is high enough, drinking more mostly produces more urine (Shirreffs et al).

Both were done in young men in a lab, not in people at bedtime, so they show which way sodium pushes rather than measuring a night's sleep. The direction is clear, though: sodium in a drink helps the body hold on to the fluid.

Will a drink with sodium make you wake up to wee?

The bigger lever is how much you drink, and when. Continence Health Australia lists "drinking large amounts of fluid, alcohol or caffeine" close to bedtime among the common reasons people get up to the toilet at night. It suggests drinking earlier in the day and gradually reducing fluids in the hours before bed, and notes that drinking too little during the day makes things harder (Continence Health Australia).

The Sleep Health Foundation says the same: drinking too much fluid, particularly at night, can be behind it, along with caffeine and alcohol, and limiting fluids shortly before bed can help but should not be overdone. It also points out that broken sleep alone can send you to the toilet, simply because you are already awake.

So the order of what matters looks like this:

1. The size of the last drink. A big glass or a mug right before lights-out is the classic trigger.
2. Alcohol and caffeine in the evening. Both are on the Australian lists. We cover alcohol in what a nightcap does to your night.
3. Waking for other reasons. If you wake at the same time most nights, the 3am article covers sleep cycles.
4. How much you drank across the day. Do most of your drinking through the afternoon and with dinner.

A small glass with sodium is a different thing from a big evening drink. It carries a modest volume, and the sodium is there to help your body hold on to it. If you ever find a particular evening has you up, the fix is the one the Australian advice gives: make the glass smaller or have it earlier.

How much is 1,000mg of sodium?

It is half of the Australian daily target, and about a quarter to a third of what the average Australian adult eats in a day.

Some context on those numbers:

• The 2,000mg figure is a target for the whole day, an average for the population. It is not an evening limit. NHMRC dropped its old 2,300mg upper limit in 2017 because it could not find a level at which blood pressure stops rising with higher intake.
• Most of the sodium Australians eat comes from packaged food. The Heart Foundation puts it at 75 to 80%, and its position statement names pizza, pastries and takeaway foods as leading sources. One small takeaway meal can pass 1,000mg on its own.
• Pink and sea salt are not lower in sodium. The Heart Foundation says all types of salt contain similar amounts. A teaspoon of any of them is about 2,000mg of sodium.
• The reference values are being reviewed. NHMRC's consultation on revised sodium values closed on 30 September 2026. The draft keeps the adult 2,000mg figure and final recommendations are expected in 2027.

The sensible way to use sodium at night is to count it in your day. If dinner was a takeaway, you may already be near your 2,000mg.

Who should check with a GP first?

If you have been told to limit salt, or you have high blood pressure or kidney problems, talk to your GP before adding sodium to your evening. The same goes if you take prescription medication (talk to your GP or pharmacist) or you are pregnant or breastfeeding (check with your GP or midwife before taking any supplement). Settl is for adults only.

How do you take sodium before bed?

Keep the volume small and the timing early in your wind-down.

• Small glass. Settl suggests one scoop in 200 to 300ml of cold water. It also dissolves in less, which tastes stronger and keeps the volume lower still.
• 30 to 60 minutes before bed. That is Settl's guidance, as the last step of the wind-down, so the drink is a small final step and not a late top-up.
• Front-load the rest. Drink most of your fluid through the day and with dinner, as set out in the hydration article.
• Watch your own nights for a week. If you are up more than before, move the glass earlier or use less water.

Where does Settl fit?

Settl is a nightly sleep powder with an electrolyte layer, one option among the ways to cover overnight hydration, alongside drinking well earlier in the day. A 9g scoop in cold water gives you about 1,000mg of sodium and about 200mg of potassium, plus 3,000mg of glycine, 200mg of L-theanine, 730mg of magnesium glycinate (146mg elemental), 900mg of inositol and chamomile extract. There is no melatonin and no sugar.

The electrolyte layer is there so eight hours without water does not wake you dried out and needing to get up. The rest of the scoop is there for the sleep: get to sleep faster, wake less at 3am, sleep deeper, wake up refreshed.

Common questions

Is it OK to have electrolytes before bed? For most healthy adults, a small glass with sodium counts toward the day's total and can fit inside the 2,000mg target if the rest of your day is modest. If you have been told to limit salt, ask your GP first.

Does salt in water before bed make you wee more? In lab trials, drinks with more sodium were retained better than drinks with less. What drives night-time toilet trips for most people is a large drink close to bed, alcohol and caffeine, so keep the glass small.

Is a pinch of pink salt in water the same as an electrolyte drink? The sodium is similar. The Heart Foundation says all salts, including pink and sea salt, contain similar amounts. A formulated drink also carries potassium and a printed, labelled dose, which is easier to count against your daily total.

How much sodium is too much at night? Australia sets a daily target of 2,000mg, not an evening one. Count the whole day, including takeaway and packaged food.

Why do I wake up to wee at night? Common reasons on the Australian lists are large drinks, alcohol or caffeine close to bed, medicines taken in the evening, hormonal changes, and simply being awake already. If it happens more than once a night and bothers you, see your GP.

The short version

Overnight is eight hours without water, and sodium helps your body hold on to the fluid it has. The volume and timing of your evening drinks matter more for toilet trips than the sodium does, so keep the last glass small and have it early in your wind-down. If you have been told to watch your salt, check with your GP first.

Get to sleep faster. Wake less at 3am. Sleep deeper. Wake up refreshed. That is what Settl is built for: magnesium glycinate, glycine, L-theanine, chamomile extract and inositol, with an electrolyte layer of about 1,000mg of sodium so eight hours without water does not wake you dried out and needing to get up. The full panel is on the ingredients page.

No melatonin. Zero sugar. Vegan. Packed in Sydney, in a TGA-licensed GMP facility.

One scoop, cold water, before bed.

Start For $69.99 Then $89.99 a month. Cancel, pause or skip anytime.

Or buy a single tub, $99 One-time order. Nothing renews.

Cheers, Roy

Sources: NHMRC and Australian Government Department of Health, Nutrient Reference Values for Australia and New Zealand, sodium; NHMRC, public consultation on draft sodium recommendations (closed 30 September 2026); Heart Foundation, "Salt and heart health" and Salt and Heart Healthy Eating position statement (2018); Continence Health Australia, "Caring for your bladder at night"; Sleep Health Foundation fact sheet on getting up at night to wee; Maughan et al, International Journal of Sport Nutrition and Exercise Metabolism, 2019; Shirreffs et al, Medicine and Science in Sports and Exercise, 1996; The George Institute for Global Health, VicHealth and Heart Foundation, salt levels in children's meals from four major fast food chains, 2019. This article explains the general research picture in plain English and is not medical advice. Talk to your GP or pharmacist about what is right for you.