New research from New Zealand shows modern medicines do not cater for the genetic makeup of Pasifika people.
Medicine research is typically carried out in Europe and the United States and tested on local populations.
But a geneticist at Wellington's Victoria University, Geoff Chambers, says a person's genetic structure affects what diseases the body responds to and how.
He says Pasifika people are shown to be more susceptible to type-two diabetes but multiple sclerosis, which is common in European communities, is virtually unheard of.
Dr Chambers says Pasifika people also tend to metabolise nicotine more slowly than European people.
"You get a patch from your doctor and you just don't get a big enough dose, so if you have patches and they don't work, the doctor winds up blaming the patient, saying you didn't try, you know, you're still smoking, I gave you the best medication, but in reality they need to have a much larger dose."
Geoff Chambers says local research is needed to ensure people are given the most effective treatment.