By Caroline Ryan
BBC News Online health staff in Berlin
Botox could be used to treat a sexual condition which prevents women having full intercourse, scientists say.
Botox has many applications
Iranian researchers have used the muscle-relaxing toxin - normally associated with wrinkle treatment - to treat women with vaginismus.
The psychosomatic condition causes muscle spasms that prevent penetrative intercourse.
Many thousands of UK women are thought to suffer from the condition, but cases are often unreported or undiagnosed.
The work was presented to the European Fertility Conference in Berlin.
Vaginismus can be triggered by traumatic events such as relationship problems or feelings of guilt about sex.
Women with the condition associate sex with pain, which can have a huge impact on their lives and on their relationships with their partners.
The aim of doctors treating the condition is to enable women to have pain-free intercourse, allowing them to break the pattern.
Botox is made from the botulinum toxin produced by the bacterium which causes botulism food poisoning.
In small quantities it can interrupt nerve impulses and paralyse muscles.
A team from the Tehran University of Medical Science treated 25 women with botox injections in muscles inside the vagina, while the patients were either lightly sedated or under general anaesthetic.
All but two were able to have pain-free intercourse with their partners after one or two treatments.
None of the women experienced any side effects from the treatment.
Dr Shirin Ghazizadeh, who led the study, told BBC News Online: "Vaginismus is a vicious cycle of pain and spasm.
"If you can't reduce the spasm, you can't reduce the pain.
"But once a patient can be engaged in satisfactory intercourse, the problem will be solved forever."
She said some of the women had been able to conceive following the treatment.
Dr Ghazizadeh said the team now plan to carry out larger scale trials where botox injections are compared to dummy injections to see if it is the toxin, or the knowledge they have been treated, which helps women.