Go to this ESSM link below and read the section on "Non-invasive methods of penile lengthening by Paolo Gontero, Marco oderda, Juan I. Martinez-Salamanca" in the ESSM publication. It kinda summarizes the research in this area to date.
ESSM: European Society for Sexual Medicine-The European Society for Sexual Medicine (ESSM) is a not-for-profit, multidisciplinary, academic and scientific organisation dedicated to male and female sexual health and dysfunction. Here’s some interesting quotes:
"Vacuum devices are used as a treatment for erectile dysfunction. A recent study assessed the long-term effect of repeated vacuum treatment for penile elongation, concluding that there is no significant physical change after 6 months of therapy: vacuum treatment of the penis was not found to be effective for penile elongation, although it provided some sort of psychological satisfaction for some men."
"Recently, great visibility has been given to penile extenders, nonsurgical devices which generate progressive mechanical traction to the penis. Although there are only a few well-conducted studies to assess their efficacy, it seems that these devices can produce an effective and durable lengthening of the penis, both in the
flaccid and in the stretched state."
"Treatment with penile extenders is generally reported to be well-tolerated, although longer daily use would probably reduce patients’ compliance, and the patients seem to be happy with the outcome. In conclusion, it seems that penile extenders are an effective treatment for patients who complain of “short penis”. The application of such devices can be recommended in all patients regardless of the penile length, because of the low risk of complications."
"Conclusion: Among the non invasive methods of penile lengthening, penile traction devices are those whose efficacy is supported by some scientific evidence. This is mainly generated by pilot studies with a prospective non comparative design and further studies are needed. While the penis can effectively be elongated by an average of 1.5-2.5 cm based on the underlying condition, there is no evidence that the girth can be increased by applying traction forces. Taking into
account that surgical methods do not rely on higher scientific background nor have shown better results, penile traction devices should be proposed as a first-line treatment option for patients seeking a penile lengthening procedure."
ESSM for Education and Science in Sexual Medicine
Starting Size: April, 28, 2010: NBPEL-7" Girth-6" (base, MSG, glans)
Currently: BPEL-8" NBPEL-7.25" Girth-6.25" (base)/6.125" (MSG)/6.125" (glans)