Viagra cannot be bought over the counter at present
The Medicines Control Agency (MCA) is considering the move, which could happen before the end of the year.
It would raise the likelihood of the anti-impotence drug being used as a social aid to revive sex lives, instead of just treatment for a medical condition.
The review is looking at whether Viagra and other prescription-only medicines should be reclassified to allow them to be sold at pharmacies in supermarkets and high streets.
The government wants more medicines to be made available over the counter, to save the NHS money.
A new fast-track system for reclassifying drugs as pharmacy medicines is expected to be approved by April.
The MCA said the earliest Viagra could become available 120 days from April, though it warned it would be likely to be longer.
It has asked the Royal Pharmaceutical Society of Great Britain to hold consultations about which drugs would be suitable as over-the-counter drugs - Viagra is one of those being considered.
A spokesman for the MCA said the list of possible drugs is for debate purposes among health professionals and the pharmaceutical industry.
He added: "Before any change to availability of a medicine can be approved it will be subject to regulatory processes requiring detailed individual assessment."
Informed choices
This would include covering the medicine's safety record and review of educational information and support materials for health professionals and patients.
"This is an issue on which views are likely to vary," he added.
"The government is committed to widening the availability of medicines where it is safe to do so and to enabling people to make informed choices about their own treatment.
"The first consideration must always be patient safety and any application to consider a particular medicine will first require data to demonstrate its safety in use.
This would involve extensive work and mean changes to medicines like Viagra are not "imminent".