Found this info on arginmax, couldn't find the actual study, which is what I was looking for.
The results of a clinical study on a nutritional supplement expressly formulated for women (ArginMax for Women) were presented at the Ninth Annual Congress on Women's Health & Gender-Based Medicine in Washington, D.C. The study indicated significant improvement in women's sexual desire and overall satisfaction, according to the co- author, Mary Lake Polan, MD, PhD, MPH, Professor and Chair, Department Of Gynecology/Obstetrics, Stanford University School of Medicine. The study results was published in the May/June issue of the peer-reviewed, "Journal of Women's Health and Gender-Based Medicine".
Sexual health encompasses both sexual desire and physiological response. A landmark study (JAMA, 1999) assessed the prevalence of sexual issues across various social and age groups. The study reported that there are many unaddressed sexual health issues among women than previously believed. Yet relatively little attention has been given to research in this area.
In this double-blind placebo-controlled study, 93 women, ages 22-73, enrolled as participants lacking in sexual desire. Of the 93 women involved, 46 received a nutritional supplement and 47 received a placebo. The participants used the Female Sexual Function Index questionnaire to rate their level of sexual health before starting the study and after taking either a placebo or the supplement.
At the end of four weeks, 62 percent of the active group reported significantly improved satisfaction with their overall sex life, compared to 38 percent in the placebo group (p<0.01)
In the active group, 64 percent reported an improvement in their level of sexual desire, compared to 43 percent in the placebo group. A sub-group of peri-menopausal women also showed similar improvements.
The nutritional supplement used in the study is a patent-pending formula that contains L-arginine, ginseng, ginkgo, damiana, and 14 other vitamins and minerals. L-arginine is an essential amino acid reported to play an important role in sexual health. Ginseng, ginkgo and the other ingredients have a long history of use. "There are a lot of herbal ingredients that are marketed for sexual health, but to our knowledge, this is the only nutritional supplement for women that is supported by any clinical testing," according to Dr. Polan.