SPV-30 is a natural herb product manufactured by Arkopharma that is extracted from an evergreen tree called the boxwood. It contains approximately 100 compounds called alkaloids, five of which have been identified: buxtauine, cyclobuxine D, boxamine, cyclovirobuxine D and cyclovirobuxine C. Four of these have shown steroid-like properties as well as anti-bacterial and anti-mycobacterial effects. There have been suggestions that SVP-30 may have an immunosuppressive effect similar to cyclosporin, and that it may be a dangerous treatment for people with advanced immunosuppression.

There have been reports that SPV-30 inhibits HIV in the test-tube, but the exact mechanism of inhibition is unclear. It is believed to be a reverse transcriptase inhibitor.

A phase I trial found that people with CD4 counts between 250 and 500 experienced an average 94 CD4 cell increase after 30 weeks of treatment. A phase II/III clinical trial among 180 people with HIV is underway at the Institut Pasteur in Paris and eleven other clinics in France. An informal US study which monitored the use of SPV-30 in approximately 400 patients found that anti-retroviral naive patients demonstrated a median fall in viral load of only 38.5% after two months, and that only 46.1% of patients had a viral load that was 0.3 log below baseline after six months. Median CD4 counts in all groups who received SPV-30 had fallen below baseline after six months on treatment. However, approximately 45% of patients reported improved quality of life, including better sleep, appetite and energy levels.

No side-effects have been reported, but the long-term use of boxwood is discouraged in herbal medicine lest it cause liver toxicities, convulsions, diarrhoea, electrolyte imbalances and even death. The safe dosage is yet to be established by clinical trials, and the medically unsupervised use of SVP-30 (or boxwood extract as a substitute for SPV-30) is not recommended.

In March 1997, the US Food and Drug Administration intervened to stop distribution of SPV-30, expressing concerns that it was neither safe nor effective for people with HIV.