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Yohimbine for erectile dysfunction update


Clinical bottom line

Yohimbine has been tested against placebo in 10 randomised trials with 659 men. Yohimbine provided satisfactory erections in 30% of men compared with 14% with placebo. The NNT compared with placebo for one man to achieve satisfactory erections was 6.4 (4.6 to 11). Adverse events were generally mild, though some men withdrew from treatment because of them.


It was decided to update the review by Ernst and colleagues , because there were more trials that could be added and in order to calculate NNTs.

Additional searching was done using PubMed, Medline and the Cochrane Library, up to September 2005. Randomised trials in which yohimbine was compared with placebo were sought. Details of the trials were abstracted and quality scoring done with a 5 point scale. For crossover or partial crossover designs, details of the first phase were used (as a parallel group trial) where possible, and where this was not possible the full crossover data was used.

The outcome sought was patient/partner judgement of satisfactory erections suitable for intercourse, or actual intercourse, at home. Ideally this was on a patient basis, rather than on event basis, which was a secondary outcome. Relative risk and NNT were calculated using standard methods.


Ten trials were found, three more than in the Ernst review. There were 335 men receiving yohimbine and 324 receiving placebo. References to papers included and other references are in the reference table at the end of the article. The dose of yohimbine was between 15 mg and 40 mg daily, for 4-10 weeks of treatment.

Details of the trials are shown in Table 1:

Table 1: Details of studies included in the analysis



Quality score





Adverse events

Kunelius et al, 1997 Randomised, double blind crossover


29 men with impotence for six months or more, of mixed type. Mean age 51 years 36 mg oral yohimbine daily or placebo for 25 days, with 14 day washout A number of penile tumescence measurements, with VAS and patient global Adequate treatment 3/27 on yohimbine and 2/27 on placebo AE withdrawals because of hypertensive crisis, and palpitation, both on yohimbine
Mann et al, 1996 Randomised, double blind parallel


31 men mixed aetiology. Mean age 43 years 15 mg oral yohimbine daily or placebo for seven weeks Number of outcomes, including penile rigidity and questionnaire On clinical global improvement scale, 9/15 yohimbine and 6/15 placebo Some minor AEs, but no apparent difference between treatments
Montorsi et al, 1994 Randomised, double blind, partial crossover


63 men recruited, with erectile dysfunction. 15 mg yohimbine daily plus trazodone 50 mg daily, or placebo, for eight weeks. Only placebo patients crossed over to treatment Patient and partner reporting complete, partial and no response Complete response 14/28 on yohimbine and 3/27 on placebo No data
Morales et al, 1994 Randomised, double blind, partial crossover


100 men with organic impotence. Mean age 56 years 18 mg oral yohimbine daily, or placebo, for 10 weeks Patient and partner reporting complete, partial and no response Complete response 11/50 on yohimbine and 7/50 on placebo No data
Navarette Hederra et al, 1992 Randomised, double blind, crossover


30 men with impotence. 17 completed both phases 16 mg oral yohimbine daily, or placebo, for 45 days Patient reporting good response. Results from 42 treatments in 25 patients Good response 5/12 on yohimbine and 3/13 on placebo Two patients reported mild AEs
Reid et al, 1987 Randomised, double blind, partial crossover


48 men with psychogenic impotence. Age 18-70 years 18 mg oral yohimbine daily, or placebo, for 10 weeks Patient and partner reporting complete, partial and no response Complete response 9/29 on yohimbine and 1/19 on placebo No data
Riley et al, 1989 Randomised, double blind, crossover


70 men recruited, with erectile dysfunction for at least six months. Mean age 50 years 16 mg oral yohimbine daily, or placebo, for 8 weeks Occurrence and quality of stimulated, morning and spontaneous erections Good stimulated erections 11/51 on yohimbine and 4/50 on placebo Four withdrawals, two each on yohimbine and placebo. Other AEs rare and minor
Rowland et al, 1997 Randomised, double blind, crossover


11 men with erectile dysfunction 5/10 mg oral yohimbine daily for a first/second two week period, or placebo Global investigator evaluation of benefit 3/11 on yohimbine and 0/11 on placebo Disturbed sleep common.
Susset et al, 1989 Randomised, double blind, partial crossover


82 impotent men. 21 mg oral yohimbine up to 42 mg daily or placebo. One month with maximum dose. Global patient/partner evaluation 10/71 on yohimbine and 3/71 on placebo 12 withdrawals on yohimbine in total
Vogt et al 1997 Randomised, double blind, parallel


86 men with erectile dysfunction. Mean age 52 years 30 mg oral yohimbine daily or placebo for eight weeks Subjective response calculated from patient diaries 24/41 on yohimbine and 16/41 on placebo 13 AE reported with yohimbine and 4 with placebo. AE withdrawals 2 and 1 respectively

Only one trial (Montorsi et al, 1994) showed a statistical benefit for yohimbine over placebo. Figure 1 shows a L'Abbé plot of the 10 trials:

Figure 1: L'Abbé plot of trials of yohimbine against placebo.

Overall, 99/335 men achieved satisfactory erections with yohimbine (30%, with 95% confidence interval of 25% to 34%). By contrast 45/324 men achieved satisfactory erections with yohimbine (14%, with 95% confidence interval of 10% to 18%). Six men would have to be treated with yohimbine for one man to achieve satisfactory erections who would not have achieved them with placebo. The NNT was 6.4 (95%CI 4.6 to 11). Studies with daily doses of 20 mg or more gave the same NNT as those with doses of 18 mg or less.

The relative benefit was 2.1 (95% CI 1.6 to 2.9).


The trials in this review were generally small, with only one studying as many as 100 men. With only 658 men in the trials, and 335 receiving yohimbine, this body of evidnece is incomplete both as regards efficacy, and more especially as regards adverse events. Some studies mentioned serious adverse events, like hypertensive crisis or palpitations. There were a number of withdrawals on yohimbine, though a number of studies made no mention of adverse events.




Ernst E, Pittler MH. Yohimbine for erectile dysfunction: a systematic review and meta-analysis of randomized clinical trials. The Journal of Urology 1998; 159:433-6.


Morales A, Condra M, Owen JA, Surridge DH, Fenemore J, Harris C. Is yohimbine effective in the treatment of organic impotence? Results of a controlled trial. J Urol 1987; 137(6):1168-72.

In Ernst review

Mann K, Klingler T, Noe S, Roschke J, Muller S, Benkert O. Effects of yohimbine on sexual experiences and nocturnal penile tumescence and rigidity in erectile dysfunction. Arch Sex Behav 1996; 25(1):1-16.

In Ernst review

Reid K, Surridge DH, Morales A et al. Double-blind trial of yohimbine in treatment of psychogenic impotence. Lancet 1987; 2(8556):421-3.

In Ernst review

Riley AJ, Goodman RE, Kellett JM, Orr R. Double blind trial of yohimbine hydrochloride in the treatment of erection inadequacy. SEX-MARIT-THER Sexual-and-Marital-Therapy. 1989; 4(1):17-26.

In Ernst review

Rowland DL, Kallan K, Slob AK. Yohimbine, erectile capacity, and sexual response in men. Arch Sex Behav 1997; 26(1):49-62.

In Ernst review

Sonda LP, Mazo R, Chancellor MB. The role of yohimbine for the treatment of erectile impotence. J Sex Marital Ther 1990; 16(1):15-21.

In Ernst review

Susset JG, Tessier CD, Wincze J, Bansal S, Malhotra C, Schwacha MG. Effect of yohimbine hydrochloride on erectile impotence: a double-blind study. J Urol 1989; 141(6):1360-3.

In Ernst review

Vogt HJ, Brandl P, Kockott G et al. Double-blind, placebo-controlled safety and efficacy trial with yohimbine hydrochloride in the treatment of nonorganic erectile dysfunction. Int J Impot Res 1997; 9(3):155-61.

In Ernst review

Kunelius P, Hakkinen J, Lukkarinen O. Is high-dose yohimbine hydrochloride effective in the treatment of mixed-type impotence? A prospective, randomized, controlled double-blind crossover study. Urology 1997; 49(3):441-4.

Not included in Ernst review - more recent

Teloken C, Rhoden EL, Sogari P, Dambros M, Souto CA. Therapeutic effects of high dose yohimbine hydrochloride on organic erectile dysfunction. J Urol 1998; 159(1):122-4.

Not retrieved by Ernst since it is more recent than his review, but not randomised

Montorsi F, Strambi LF, Guazzoni G et al. Effect of yohimbine-trazodone on psychogenic impotence: a randomized, double-blind, placebo-controlled study. Urology 1994; 44(5):732-6.

Not included in Ernst review

Navarrete Hederra As et al. Tratamiento de la disfunci¢n erectil con yohimbina: estudio randomizado doble ciego con placebo / Erectile disfunction418 treatment with yohimbine: double blind study randomized with placebo. Rev.-Chil.-Urol 1993; 57:54-7.

RCT not in Ernst review

Yohimbine for male sexual dysfunction. Med Lett Drugs Ther 1994; 36(938):115-6.


Carey MP, Johnson BT. Effectiveness of yohimbine in the treatment of erectile disorder: four meta-analytic integrations. Arch Sex Behav 1996; 25(4):341-60.

Data synthesis

Vrzàk G. Yohimbine for impaired erection. TW-UROL-NEPHROL TW-Urologie-Nephrologie. 1991; 3(5):266.


Bastian HP, Muller J. Yohimbine in the treatment of male impotence. THERAPIEWOCHE Therapiewoche. 1991; 41(10):603-6.


Hartmann U, Stief CG, Djamilian M et al. Oral therapy trial of erectile dysfunction in selected patients. UROLOGE-AUSG-B Urologe-Ausgabe-B. 1991; 31(5):204-6.


Haslam MT. A trial of idazoxan and yohimbine in erectile dysfunction. Sexual & Marital Therapy. 1992; 7:261-6.

Yohimbine not given as part of the RCT

Imagawa A, Kawanishi Y. Clinical study on male sexual dysfunction. Report 5: Oral administration of yohimbine for the treatment of male impotence. NISHINIHON-J-UROL Nishinihon-Journal-of-Urology. 1987; 49(1):77-81.


Knoll LD, Benson RC Jr, Bilhartz DL, Minich PJ, Furlow WL. A randomized crossover study using yohimbine and isoxsuprine versus pentoxifylline in the management of vasculogenic impotence [see comments]. J Urol 1996; 155(1):144-6.

No placebo. Yohimbine not given alone

Morales A, Surridge DHC, Marshall PG, Fenemore J. Nonhormonal pharmacological treatment of organic impotence. J-UROL Journal-of-Urology. 1982; 128(1):45-7.