WA women will soon have access to an abortion drug that has been shown to be almost as effective and safe as the controversial pill RU486.

The sexual health group Marie Stopes International confirmed yesterday that after a three-month pilot in its Sydney clinics, the drug methotrexate would be available from its eight Australian medical centres, including clinics in Midland and Kwinana, in the new year.

Methotrexate, which is designed to treat cancer and end ectopic pregnancies, has been combined with another drug, misoprostol, which is sometimes used to treat stomach ulcers. Together, they are considered almost as effective as RU486.

Of the 36 women who were given the combination therapy, only one needed to have a surgical abortion because the drugs failed. More than 85 per cent of the women in the trial said they were happy with the drug.

Marie Stopes senior doctor Philip Goldstone said the women had not suffered any adverse effects from the methotrexate, but the misoprostol had caused some expected side effects such as diarrhoea, nausea and vomiting.

The pilot trial would continue in NSW until the end of the month, and staff at clinics in WA, ACT and Queensland would undergo training early in the new year so they could offer the treatment to women soon after. Dr Goldstone said it was the best option while RU486 was not available for mainstream use.

"Methotrexate can be used up to seven weeks into the pregnancy, after which time its efficacy really drops off," he said.

"This compares to about nine weeks with RU486.

"RU486 would still be our preferred option, because it's slightly more effective, but even that's not enormous, we're talking about 94-96 per cent with methotrexate compared to 98 per cent with RU486.

"RU486 is a bit more predictable and has a shorter course but while we don't really have it available methotrexate is a safe and effective option."