Valentine’s Day: a good time to look at libido-boosters?

Today is Valentine’s Day, a good moment to take a critical look at some of the libido-boosters so-called alternative medicine (SCAM) has to offer. The Internet offers plenty; this website, for instance, advertises over 20 different natural (mostly botanical) products. But such sites are typically thin on evidence.

A quick Medline search locates plenty of research. Much of it seems to be on rats which is not so relevant – unless, of course, your husband is a rat. In terms of clinical trials, Medline too is not all that informative. Here are some of the studies I found:

Eurycoma longifolia is reputed as an aphrodisiac and remedy for decreased male libido. A randomized, double-blind, placebo controlled, parallel group study was carried out to investigate the clinical evidence of E. longifolia in men. The 12-week study in 109 men between 30 and 55 years of age consisted of either treatment of 300 mg of water extract of E. longifolia (Physta) or placebo. Primary endpoints were the Quality of Life investigated by SF-36 questionnaire and Sexual Well-Being investigated by International Index of Erectile Function (IIEF) and Sexual Health Questionnaires (SHQ); Seminal Fluid Analysis (SFA), fat mass and safety profiles. Repeated measures ANOVA analysis was used to compare changes in the endpoints. The E. longifolia (EL) group significantly improved in the domain Physical Functioning of SF-36, from baseline to week 12 compared to placebo (P = 0.006) and in between group at week 12 (P = 0.028). The EL group showed higher scores in the overall Erectile Function domain in IIEF (P < 0.001), sexual libido (14% by week 12), SFA- with sperm motility at 44.4%, and semen volume at 18.2% at the end of treatment. Subjects with BMI ≥ 25 kg/m(2) significantly improved in fat mass lost (P = 0.008). All safety parameters were comparable to placebo.

Yoga is a popular form of complementary and alternative treatment. It is practiced both in developing and developed countries. Use of yoga for various bodily ailments is recommended in ancient ayvurvedic (ayus = life, veda = knowledge) texts and is being increasingly investigated scientifically. Many patients and yoga protagonists claim that it is useful in sexual disorders. We are interested in knowing if it works for patients with premature ejaculation (PE) and in comparing its efficacy with fluoxetine, a known treatment option for PE.  Aim: To know if yoga could be tried as a treatment option in PE and to compare it with fluoxetine.  Methods: A total of 68 patients (38 yoga group; 30 fluoxetine group) attending the outpatient department of psychiatry of a tertiary care hospital were enrolled in the present study. Both subjective and objective assessment tools were administered to evaluate the efficacy of the yoga and fluoxetine in PE. Three patients dropped out of the study citing their inability to cope up with the yoga schedule as the reason.  Main outcome measure: Intravaginal ejaculatory latencies in yoga group and fluoxetine control groups.  Results: We found that all 38 patients (25-65.7% = good, 13-34.2% = fair) belonging to yoga and 25 out of 30 of the fluoxetine group (82.3%) had statistically significant improvement in PE.  Conclusions: Yoga appears to be a feasible, safe, effective and acceptable nonpharmacological option for PE. More studies involving larger patients could be carried out to establish its utility in this condition.

Antidepressants including selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenaline reuptake inhibitors (SNRIs) are known to cause secondary sexual dysfunction with prevalence rates as high as 50%-90%. Emerging research is establishing that acupuncture may be an effective treatment modality for sexual dysfunction including impotence, loss of libido, and an inability to orgasm.  Objectives: The purpose of this study was to examine the potential benefits of acupuncture in the management of sexual dysfunction secondary to SSRIs and SNRIs.  Subjects: Practitioners at the START Clinic referred participants experiencing adverse sexual events from their antidepressant medication for acupuncture treatment at the Mood and Anxiety Disorders, a tertiary care mood and anxiety disorder clinic in Toronto.  Design: Participants received a Traditional Chinese Medicine assessment and followed an acupuncture protocol for 12 consecutive weeks. The acupuncture points used were Kidney 3, Governing Vessel 4, Urinary Bladder 23, with Heart 7 and Pericardium 6. Participants also completed a questionnaire package on a weekly basis.  Outcomes measured: The questionnaire package consisted of self-report measures assessing symptoms of depression, anxiety, and various aspects of sexual function.  Results: Significant improvement among male participants was noted in all areas of sexual functioning, as well as in both anxiety and depressive symptoms. Female participants reported a significant improvement in libido and lubrication and a nonsignificant trend toward improvement in several other areas of function.  Conclusions: This study suggests a potential role for acupuncture in the treatment of the sexual side-effects of SSRIs and SNRIs as well for a potential benefit of integrating medical and complementary and alternative practitioners.

The primary objectives were to compare the efficacy of extracts of the plant Tribulus terrestris (TT; marketed as Tribestan), in comparison with placebo, for the treatment of men with erectile dysfunction (ED) and with or without hypoactive sexual desire disorder (HSDD), as well as to monitor the safety profile of the drug. The secondary objective was to evaluate the level of lipids in blood during treatment.  Participants and design: Phase IV, prospective, randomized, double-blind, placebo-controlled clinical trial in parallel groups. This study included 180 males aged between 18 and 65 years with mild or moderate ED and with or without HSDD: 90 were randomized to TT and 90 to placebo. Patients with ED and hypertension, diabetes mellitus, and metabolic syndrome were included in the study. In the trial, an herbal medicine intervention of Bulgarian origin was used (Tribestan®, Sopharma AD). Each Tribestan film-coated tablet contains the active substance Tribulus terrestris, herba extractum siccum (35-45:1) 250mg which is standardized to furostanol saponins (not less than 112.5mg). Each patient received orally 3×2 film-coated tablets daily after meals, during the 12-week treatment period. At the end of each month, participants’ sexual function, including ED, was assessed by International Index of Erectile Function (IIEF) Questionnaire and Global Efficacy Question (GEQ). Several biochemical parameters were also determined. The primary outcome measure was the change in IIEF score after 12 weeks of treatment. Complete randomization (random sorting using maximum allowable% deviation) with an equal number of patients in each sequence was used. This randomization algorithm has the restriction that unequal treatment allocation is not allowed; that is, all groups must have the same target sample size. Patients, investigational staff, and data collectors were blinded to treatment. All outcome assessors were also blinded to group allocation.  Results: 86 patients in each group completed the study. The IIEF score improved significantly in the TT group compared with the placebo group (Р<0.0001). For intention-to-treat (ITT) there was a statistically significant difference in change from baseline of IIEF scores. The difference between TT and placebo was 2.70 (95% CI 1.40, 4.01) for the ITT population. A statistically significant difference between TT and placebo was found for Intercourse Satisfaction (p=0.0005), Orgasmic Function (p=0.0325), Sexual Desire (p=0.0038), Overall Satisfaction (p=0.0028) as well as in GEQ responses (p<0.0001), in favour of TT. There were no differences in the incidence of adverse events (AEs) between the two groups and the therapy was well tolerated. There were no drug-related serious AEs. Following the 12-week treatment period, significant improvement in sexual function was observed with TT compared with placebo in men with mild to moderate ED. TT was generally well tolerated for the treatment of ED.

What makes me suspicious about these trials is that:

• they are mostly on the flimsy side,
• there are as good as no independent replications,
• they all report positive outcomes. I was unable to find a single study where the authors concluded: SORRY, BUT THIS STUFF IS USELESS!

Disappointed with the quality and the content of the existing trials, I am now off to buy some oysters!