020 7486 3840

About the team

David Ralph - St Peters Andrology Centre London

Mr David Ralph BSc MS FRCS(Urol)

Consultant Uroandrologist

David Ralph is a Consultant Urologist at the Institute of Urology, London. He has a wide interest in all aspects of sexual medicine and leads an active research programme with PhD and MD fellows.  He has written many chapters on Peyronie’s disease and the surgical and medical management of erectile dysfunction.  He is the biggest implanter of penile prostheses in the UK with two clinical fellowship programmes to teach on this.
He is an accomplished microsurgeon who established and teaches on the Royal College of Surgeons Microsurgery for Andrologists course. In clinical practice his microsurgery skills are of particular benefit to men requiring surgery for fertility problems or vasectomy reversal.
David Ralph has previously been President of the British Association of Urological Surgeons (BAUS) section of Andrology and British Society for Sexual Medicine (BSSM). He organized the European Society of Sexual Medicine (ESSM) Congress in London in 2004. He is heavily involved in the patient organizations of the Sexual Dysfunction Association (SDA) in the UK and its European equivalent ESDA.

Visit Mr David Ralph's website

Nim Christopher - St Peters Andrology Centre London

Mr Nim Christopher MPhil FRCS(Urol)

Consultant Uroandrologist

Nim Christopher is a Consultant Urologist at the Institute of Urology, London where he specialises entirely in Uroandrology. He was born in Malaysia and studied medicine at St Bartholomew's Hospital, London graduating from there in 1987. Since then he has worked mainly in Cambridge and London achieving an MPhil (Cantab) in 1995 and Specialist FRCS(Urology) in 2000..

He is an extremely accomplished microsurgeon with a specialist interest in functional and structural penile problems as well as male factor infertility. As such he has played a central role in the development of our phalloplasty techniques and is heavily committed to our work in this area.

He is a member of the British Association of Urological Surgeons (Andrology section), British and European Society of Sexual Medicine and a reviewer for the Journal of Sexual Medicine, British Journal of Urology International and Asian Journal of Andrology.

Dr John Dean FRCGP

Consultant in Sexual Medicine

John Dean is a Sexual Physician and Clinical Director of Sexual and Gender Medicine with Devon Partnership NHS Trust. He is a Londoner by birth and graduated from The Middlesex Hospital Medical School, University of London, in 1981.

He provides education, assessment and treatment for men, women and couples with sexual function concerns, or who need advice about their general health and medical care, and its impact upon their sexuality, and for people with concerns about gender identity. His clinical interests include the preservation and rehabilitation of sexual function after cancer treatment, all aspects of care for women with sexual function concerns, androgen deficiency in both men and women, the relationship between cardiovascular disease and sexual function problems, and gender identity problems.

He is actively involved in pharmaceutical development and advises several companies developing treatments for erectile dysfunction, premature ejaculation, and desire and arousal problems experienced by women. His approach to both individual and couple care is holistic, paying appropriate attention to psychological, behavioural, relationship and cultural factors, as well as medical factors.

Dr Dean has published over 60 articles and clinical research papers, and has authored or contributed to five books on Sexual Medicine subjects. He is President-Elect of the International Society for Sexual Medicine and Secretary-General of the European Society for Sexual Medicine. He is a member of numerous national and international committees related to his specialty and is a Course Director of the ESSM specialist training programme for future Sexual Physicians. He is also chairman of the ethics committees of the Journal of Sexual Medicine and the International Society for the Study of Women’s Sexual Health.


Consultant Genitourinary Physician

Philip Kell is a sexual health physician who undertook his training in Medicine at University of Sydney where he graduated in 1979 with a Bachelor of Medicine/Science. He came to the UK in 1984 and completed postgraduate training in obstetrics and gynaecology and genito-urinary medicine. He is presently employed by Maidstone and Tunbridge Wells NHS Trust in Kent, and University College London Hospital.

He sees both male and female patients with a wide range of sexual health problems including sexually transmitted infections, sexual dysfunction, gender identity issues and genital dysmorphophobia. Particular interests include problems of pelvic pain and hormone replacement therapy. He enjoys working in close cooperation with his surgical colleagues who benefit from his broad range of experience.

Dr Kell has a strong interest in research into sexual function doing both basic science work in conjunction with the UCL laboratories as well as clinical research with pharmaceutical companies.

He is the chair of the national training committee for genito-urinary medicine, the treasurer of the British Society for Sexual Medicine, past chairman of the British Association of Sexual Health's special interest group in sexual dysfunction and one of the authors of the national guidelines for the management of erectile dysfunction.

 Evangelos Zacharakis - St Peters Andrology Centre London

Mr. Evangelos Zacharakis PhD FRCS(Eng), FECSM, FEAA

Consultant Urological Surgeon

Evangelos Zacharakis is a consultant urological surgeon at Guy's Hospital and Member of St Peter’s Andrology Centre..He completed his higher surgical training in University College Hospital London, undertaking a four-year fellowship in reconstructive urology and andrology. Evangelos then spent two more years doing a fellowship in robotic and laparoscopic urology.

Evangelos performs a range of general urological procedures and has a specialist interest in genital reconstruction, genito-urethral surgery, Peyronie’s disease, erectile dysfunction including implant surgery, male incontinence and the investigation and management of male factor infertility. 

He has been invited as a speaker as well as a surgeon (performing live surgery) and also has chaired scientific meetings both nationally and internationally in the field of genito-urethral reconstructive and andrological surgery. He is also referee to a number of scientific journals and has published over 100 abstracts, papers and book chapters on the subject of reconstructive urology, andrology and uro-oncology. Evangelos is actively involved in the teaching and training of surgeons in the UK and overseas. 

To find out more about Evangelos Zacharakis, download his CV.