Did you know that you can get Calpol and other medicines for your children free? Until this week, hardly anybody did.
But after one mother posted about the scheme on Facebook, thousands of people have discovered that those who don't have to pay for prescriptions, such as children and the over-60s, are eligible for the NHS's Minor Ailments Scheme.
"I was in Boots yesterday buying Calpol and happened to complain to the cashier how expensive it is. She told me to my amazement that if you register your details with them under the 'minor ailments scheme' that all medicines etc. for children are free. A scheme that has been going for 8 years," wrote Christine Davidson, of Stornoway, Scotland.
"They are not allowed to advertise it, but you can save a small fortune on Calpol, Piriton, Sudocrem, plasters, etc.!! I wish I had known 8 years ago!"
Her post has now been shared more than 100,000 times.
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The aim of the Minor Ailments Scheme was to take pressure off GPs by allowing people on low incomes to go straight to a pharmacist for remedies for minor conditions.
"Medicines are only available via this scheme to those who genuinely need them and would otherwise have to go to visit a GP to obtain a prescription to access them," says the NHS.
Free treatments are only available for current health problems - not to be stored for future use - and will only be given to patients registered with a GP in the area.
The NHS asks patients to use the service responsibly.
"Naturally, the NHS budget isn't infinite," a spokesman for NHS Salford Clinical Commissioning Group, told the Manchester Evening News.
"If a patient presents with enough frequency to cause the pharmacist concern that they might be abusing the scheme in anyway, then pharmacists are advised to refer that person back to their GP for treatment."
The free medicines are only available from participating pharmacies, and the ailments covered can vary from area to area based on local need. In some places, there's just a seasonal scheme offering free treatments for coughs and colds.
Illnesses potentially eligible for the Minor Ailment Scheme:
Headache and fever
Heartburn and indigestion
Insect bites and stings
Mild eczema and dermatitis
Verrucas and warts