Researchers comparing maggots with a standard "hydrogel" in treating leg ulcers found little difference.
Recent excitement over using maggots to speed up healing and even reduce MRSA infections in leg ulcers seems to have been premature, they said.
The study, published in The British Medical Journal, is the first to compare maggots with standard treatment.
Leg ulcers can be very difficult to treat and after use of high-compression bandages only about half are healed within 16 weeks.
One common treatment is to use a water-based gel to keep the wound moist and promote the natural healing process.
Maggots, or larval therapy, are another option - but it can be more tricky to place them in the wound and they have to be specially ordered which takes a few days.
The theory has been that maggots are effective because they "clean out" dead tissue - a process called debridement - stimulating healing and getting rid of bugs such as MRSA in the process.
But although larval therapy is being used more and more, it has only been tested in one randomised controlled trial of 12 patients, the team said.
In the latest study, 270 patients with leg ulcers from around the UK were treated either with maggots or hydrogel and progress followed for up to a year. There was no significant difference in the time it took the ulcer to heal between the two treatments or in quality of life.
