An ointment containing the anti-herpes drug, acyclovir, has received approval from the Food and Drug Administration and is now available, by prescription, at area drug stores.

The ointment, manufactured by Burroughs Wellcome Co. is called Zovirax.

Although it is not a cure, the drug helps significantly in initial outbreaks of the persistent virus. (There are an estimated 300,000 new cases every year.) It enhances healing and limits the period in which the virus can be transmitted to others. It is less effective in treating recurrences, but still seems to shorten the contagious period.

If you think you have contracted herpes, there are two area clinics providing inexpensive diagnostic procedures:

* Northern Virginia Women's Medical Center, 280-1500, will do cultures for $10 and provide prescriptions for (and samples of) the new ointment. The Center's next (free) seminar on herpes is at 7:30 p.m. June 2 at the clinic, 3918 Prosperity Ave. Fairfax, Va. 22031.

* Sigma Reproductive Health Center in Wheaton, 881-4700, also will do cultures for $10.

For further information on herpes, support groups in the area and other sources of medical assistance write Washington HELP, P.O. Box 32326, Washington, D.C. 20007. HELP's telephone hot line has been suspended temporarily.