Jes Extender Study Result
Results from a scientific study of 50 men that used Jes Extender
- Averagely 5.6 cm (3.2 inch) permanent longer penis in 6 months
A scientific study conducted by Jorn Ege Siana, MD, was published in April 2001 to be presented at The International Congress of Urologists and specialised surgeons in June 2001.
The aim of the study was to determine the average increase of the penis length while using The Jes Extender. The observation group consisted of 50 males with an average age of 32 years. The average time span was 17 weeks, and a daily use of the extender was 8-12 hours.
Below is a summary of the statistical data:
| RESULTS OF THE STUDY | Average | Minimum | Maximum |
| Net increase in erection | 3.03 cm | 2.5 cm | 5 cm |
| Erection before study | 13.93 cm | 9 cm | 17 cm |
| Erection after study | 16.96 cm | 13 cm | 20 cm |
| Elongation per week | 0.179 cm | 0.13 cm | 0.25 cm |
| DATA | - | - | - |
| Age / years | 32 | 20 | 48 |
| Observation period / weeks | 17 | 12 | 20 |
| Daily use in ( hours ) per day | N/A | 8 | 12 |
| Pressure used ( grams ) | N/A | 1.200 g | 1.800 g |
A similar scientific study conducted by Jorn Ege Siana, MD, in 1999 with an evaluation of 18 men concluded an average increase of 2.8 cm / 1.1 inches achieved after 16 weeks of treatment. After 12 months the average 
permanent gain were 5.6 cm / 2.2 inches.
A study carried out in 1998 based on 6 men confirmed that when using a tractive force of less than 900 grams then the increase in penis length became much less than using 1200-1800 grams.
The Jes Extender has proven to be an effective way to permanently increase the length of the penis.