"Fasting" means not eating or drinking for a set time before your anaesthetic. It
matters for your safety - it lowers the risk of stomach contents entering your lungs while you
are under anaesthesia.
Your hospital will give you exact fasting times - always follow those. Times can differ
depending on your operation, your health, and the time of your surgery. The information below is
a general guide only. If your hospital's instructions differ from this page, follow the hospital.
Taking a GLP-1 medicine such as Ozempic, Wegovy or Mounjaro? Your fasting is different from the
standard advice on this page. Please follow the
GLP-1 medications before surgery guidance instead.
Work out my fasting times
Enter the date and time of your surgery to see your personalised fasting times. This is a general
guide based on the standard 6-hour and 2-hour rules - your hospital's exact times still apply.
Stop eating solid food (and milk or milky drinks). A light meal is fine up to this point unless told otherwise.
Stop clear fluids. Up to this time you may have small amounts of clear fluids - water, clear cordial, pulp-free apple juice, or black tea/coffee (no milk).
A general guide for adults
6 hours before
Stop eating solid food, and stop milk or drinks that contain milk (such as a coffee with milk). A light meal is fine up to this point unless told otherwise.
2 hours before
Stop clear fluids. Up until 2 hours before, you may have small amounts of clear fluids - water, clear cordial, pulp-free apple juice, or black tea/coffee (no milk).
On waking / before you leave
If your hospital allows, a few sips of water to take essential medicines is usually fine - but check this with them first.
What counts as a "clear fluid"?
A clear fluid is one you can see through. Yes: water, clear cordial, black tea or coffee
(no milk), pulp-free clear apple juice. No: milk, milky tea or coffee, smoothies, juice
with pulp, alcohol.
Under modern fasting guidelines, many clear carbonated soft drinks (for example clear lemonade)
are counted as clear fluids. However, some hospitals still ask you to avoid fizzy drinks before
surgery - if your hospital's instructions differ from this, follow your hospital.
Your usual medicines
Keep taking your regular medicines as normal unless you have been told otherwise. Some medicines
(for example certain diabetes or blood-thinning medicines) may need to be adjusted before
surgery. If you are unsure, ask the hospital, your surgeon, or your GP - do not stop important
medicines without advice.
Other things to avoid
No chewing gum or lollies inside the fasting window - they count as eating.
No smoking or vaping on the day before surgery if you can avoid it.
Do not drink alcohol the night before or the day of surgery.
If you accidentally eat or drink inside your fasting window, do not just turn up - tell the
hospital as soon as you can. Your surgery may need to be delayed for your safety.