Findings presented at the Eleventh International Conference of Rodent
Biology, Myshkin, Russia, July 24-28, 2008

Lu CJ, Wang KS, Chen RT, Leu TW

Institutes of Zoology, National Yang Ming University, Taipei 115, Taiwan, Republic of China.

Full article published in:
Zoological Studies, issue V, 2008, pp 762-778

Full text available through IgentaConnect - $74.00 plus tax

ABSTRACT

There are numerous reports, both in the scientific and the popular literature, that ascribe an almost magic power to Eurycoma longifolia (tongkat ali) to increase penis size in humans.

The pharmaceurical industry, which sees Eurycoma longifolia primarily as a last-line-of-defence medication against malaria and some cancers, has been listing penile hypertrophy as a possible side effect of Eurycoma longifolia.

This study has been conducted with the aim to investigate any connection between Eurycoma longifolia and penis size in the animal model.

For this animal model, rabbits and marmots where used, at various stages of their adult lives.

Raw Eurycoma longifolia root chips were obtained from Indonesia. A fresh water-based extract with a ratio of 1:40 was then prepared.

As other effects of Eurycoma longifolia were of no concern, maximum dosages as they would otherwise only be used in LD50 studies were applied.

The genitals of all test objects were measured at the beginning of the trial and on the same day of following weeks for a period of four months. In order to exclude discrepancies caused by sexual stimulation, all measuring was undertaken in the total absence of female animals and at a down-regulated room temperature of 16 degree centigrade,

Untreated animals of the same age range served as controls.

RESULT: In 8 out of 10 objects of the treated group, there was an increase of penis size of 0.3 to 0.6 above baseline 1.0. In the control group, there was an increase of 0.1 to 0.2 above baseline in 2 out of 4 animals.

The result of the study suggests that oral Eurycoma longifolia indeed may cause penile hypertrophy, possibly via the testosterone synthesis pathway. Further studies will be needed to verify the results.

 

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Test object Max in his cage

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Genital comparison Hero

Photo documentation for several test objects:

Bob (rabbit, 9 months), Hero (rabbit, 14 months), Hu (marmot, 5 months), Lee (marmot, 6 months), Lin (marmot, 6 months), Max (rabbit, 6 months), Wang (marmot, 5 months), Yong (marmot, 6 months)