• Clitoris;
  • Vascular;
  • Nitric Oxide;
  • Donor Gel;
  • Female;
  • Sexual Function;
  • FSFI;
  • Clitoral Blood Flow


Introduction.  The clitoral blood flow increase is dependent of nitric oxide (NO) and it occurs due to sexual arousal. Female sexual disorder mechanisms are poorly understood and NO therapeutic role in this scenario is to be determined.

Aim.  To assess topic NO donor S-nitrosoglutationa (GSNO) gel—100 µM effect on clitoral blood flow in healthy women.

Methods.  Forty healthy women were double-blinded randomized for Group 1, GSNO gel, n = 20 and Group 2, placebo gel, n = 20. All patients underwent Doppler ultrasound test in the clitoral artery. Hemodynamic analysis consisted of: systolic peak speed, diastolic speed, and vase resistance rate. Ten random patients were analyzed regarding sexual function after two double-blinded placebo and NO donor gel periods of 30 days.

Main Outcome Measures.  To consider female sexual dysfunction treatment through local NO-dependent pathway.

Results.  Mean age was 31 years (20–39) and mean female sexual function index score 31.5 (26–34). Group 1: The mean and standard deviation baseline and 15 minutes after the application of the GSNO gel systolic (11.7 ± 2.1 cm/second to 15.9 ± 2.4 cm/second) and diastolic speeds (2.7 ± 0.3 cm/second to 4.2 ± 0.4 cm/second) and resistance (0.71 ± 0.04 to 1.38 ± 0.06) were significantly increased (P = 0.002) (P = 0.043), and (P = 0.005), respectively. No local or systemic adverse effect was observed in women or in their sexual partners and the sexual function presented a slightly insignificant improvement (P = 0.065), although eight of 10 women could subjectively identify the GSNO gel as the preferred and most pleasant between both tried. Group 2 presented no significant differences at baseline and 15 minutes after the application of the placebo gel, P > 0.05.

Conclusion.  The topic GSNO gel increased significantly the clitoral blood flow and could be considered therapeutically in selected cases of female sexual dysfunction warranting further investigation. Souto S, Palma P, Seabra AB, Fregonesi A, Palma T, and Reis LO. Vascular modifications of the clitoris induced by topic nitric oxide donor gel—Preliminary study. J Sex Med 2011;8:484–488.