Online consultations may not be the key to reducing doctors' workload and cutting patient waiting time, a health service study has found.
NHS England is offering a £45m fund to support GP practices to adopt online consultation systems.
But researchers say evidence from a pilot shows the use and effectiveness of it is "limited".
eConsult said it had implemented recommendations from the research following a 15-month pilot.
The National Institute for Health Research-funded study evaluated eConsult – where patients can submit their symptoms to a GP electronically – which was piloted in 36 GP practices in Bristol, North Somerset and South Gloucestershire.
It discovered 38% of the online consultations led to a face-to-face contact and a further 32% led to a phone consultation.
The study, which was carried out by academics at the University of Bristol, also found usage was low at two online consultations per 1,000 patients.
It said usage was lowest out of hours, especially at the weekend.
Dr Jeremy Horwood, from the University of Bristol's Centre for Academic Primary Care, said the research concluded any practice's plan to move to electronic consultation needed to be "carefully implemented and effectively marketed".
"Online consultations may have value for some patients, such as straightforward medical enquiries, but they cannot replace face-to-face consultations in situations which are more complex," he said.
The most common reason for an online consultation was for administrative reasons such as requesting "fit notes" or repeat prescriptions, followed by infections or back or knee pain issues.
Most patients said they valued the eConsult system and clinicians said it worked best for "simple and routine inquiries" they could respond to without the need for a face-to-face or telephone follow up.
The research has been published in the medical journal BMJ Open and the British Journal of General Practice.
An eConsult spokeswoman said it had made changes including allowing patients to consult for multiple symptoms for both new and existing conditions.
She added this included allowing photo uploads, the ability to nominate a GP, simplifying language and additional long-term condition content.
NHS England has been contacted by the BBC for comment.