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expert reaction to study on contraceptive efficacy of Vasalgel in male rhesus monkeys

New research publishing in Basic and Clinical Andrology reports that new contraceptive “Vasalgel” provided effective birth control in rhesus monkey groups for more than one year.


Prof. Adam Balen, Chair of the British Fertility Society said:

“This is an interesting technique that achieves a reversible “vasectomy” by blocking the passage of sperm with a substance that later can be flushed out. If free of side effects then this novel approach has the potential for great promise as a male contraceptive. It is essential to know that the reversibility remains, irrespective of the duration of use.”


Prof. Richard Anderson, Elsie Inglis Professor of Clinical Reproductive Sciences, and Head of Section of Obstetrics and Gynaecology, University of Edinburgh, said:

“This is an interesting study taking forward a promising approach to male contraception. As an ‘efficacy’ study showing real-world effectiveness, this is very promising, and while it was not designed to investigate complications or reversibility, these may have benefits compared to vasectomy. Similar approaches have been tested in men in the past, and perhaps this will be able to be taken forward for men as well.”


Prof. Allan Pacey, Professor of Andrology, University of Sheffield, said:

“The idea of trying to replace the traditional method of vasectomy by inserting a gel into the tube which carries sperm from the testicles to the penis at ejaculation is not a new one. However, we haven’t seen much progress in developing the idea in recent years, so this study is a useful step in the right direction.

“The study shows that, in adult male monkeys at least, the gel is an effective form of contraception. But in order for it to have a chance of replacing the traditional surgical method of vasectomy, the authors need to show that the procedure is reversible and its reassuring that apparently such studies are ongoing.

“It’s interesting that there has been very little commercial interest from pharmaceutical companies in this kind of a approach and so the idea of a social venture company to develop the idea is intriguing. I would imagine there is a worldwide market for a new male contraceptive, but trials in humans and more long-term safety data are required before we will know if it is a success.”


* ‘The contraceptive efficacy of intravas injection of Vasalgel™ for adult male rhesus monkeys’ by Angela Colagross-Schouten et al. will be published in Basic and Clinical Andrology on Tuesday 7th February.


All our previous output on this subject can be seen at this weblink:


Declared interests

Prof. Adam Balen: ‘No COI’

Prof. Allan Pacey: “Chairman of the advisory committee of the UK National External Quality Assurance Schemes in Andrology, Editor in Chief of Human Fertility and Trustee of the Progress Educational Trust (all unpaid). Also, recent work for the World Health Organisation, British Broadcasting Corporation, Purple Orchid Pharma (paid consultancy with all monies going to University of Sheffield). Co-applicant on a research grant from the Medical Research Council (ref: MR/M010473/1).”

None others received.

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