Australians are being encouraged to be more discerning about where they source health advice, with the majority of 18-34-year-olds turning to "Dr Google".

Almost four out of five young Australians turn to "Dr Google" for advice about their health and medicines, according to a new survey.

This has led to warnings for people to be a little wiser about "dodgy" online health sites.

The research, commissioned by health advocacy group NPS MedicineWise, has found the majority of people aged 18-34 go online to source health-related information.

Almost 80 per cent of the survey's participants admitted they will sometimes or always look up information about their health conditions on the internet to avoid seeing a health professional.

This is an increase on the last NPS MedicineWise survey conducted in 2012.

The Galaxy Research survey also showed 20 per cent of participants would use Facebook to ask questions about medicines.

NPS MedicineWise spokeswoman and pharmacist Aine Heaney says people need to be a bit more discerning.

"They need to be aware that there's lots of dodgy information that's on the internet these days," she said.

While it is always a good idea to equip yourself with health-related information, Ms Heaney says it's important to be aware that not all health information you access on the internet will be accurate or reliable.

"Some might be full of medical jargon and not have plain language statements to explain the information clearly."

"You need to be able to assess the reliability of information found on the internet, and understand limitations of what the internet can tell you."

If people are wanting more information about the medicines they've been prescribed then they should seek advice from a health professional or pharmacist. They can also ring the drug manufacturer.