There is little evidence teething gels containing an anaesthetic are effective at easing pain, the medicines regulator has said.
The gels for children and babies are available in High Street shops.
But from next year those containing lidocaine – the anaesthetic used in many gels – will be available only in pharmacies.
Parents have been advised to massage the gums or use a teething ring before trying the gels.
The guidance comes from the Medicines and Healthcare products Regulatory Agency (MHRA), which said instructions about using the gels and safety warnings for them should also be updated.
Its review found there was a "very small" risk of harm associated with using gels containing lidocaine and they should be used only as a second line of treatment following discussions with a healthcare professional.
Dr Sarah Branch, from the the MHRA, said: "Our review showed there is a lack of evidence of benefit to using teething gels.
"To help babies and children with teething, parents and caregivers should try non-medicine options such as rubbing or massaging the gums or a teething ring.
"We want to make sure you get the right information about teething.
"If your child continues to have problems with teething, talk to your pharmacist or healthcare professional about the best options."
Dr Cheryll Adams, executive director of the Institute of Health Visiting, said "teething was a normal process".
She added: "Parents should talk to their health visitors if they are concerned that their baby is overly distressed but their first action should be to offer the baby a cold teething ring or similar to bite on to relieve their discomfort and/or to massage the baby's gums with a clean finger.
"If this isn't effective and the baby is persistently distressed, then they can speak to a pharmacist, who may feel that it's appropriate to offer a pharmaceutical treatment."