Project Goals


Ultrasound delivered from a therapeutic instrument has sufficient power and the appropriate frequency to cause the loss of germ cells from the testis.  The mechanism for this germ cell loss is currently unknown.  Studies from the 1970s assert that the loss of fertility after ultrasound treatment can be reversible, depending upon the dose used.  Little work has been published on this method since these early reports.

The Purpose (Mission)

  • Provide men wishing to share responsibility for family planning with a long-lasting, non-invasive, non-hormonal alternative to current methods of male birth control.

Targets and Timeline

  • Optimize the ultrasound treatment parameters during the first quarter of the project period.
  • Demonstrate that the contraceptive effect is safe and reversible during the second quarter of the project period. 
  • Begin determining the effect of using multiple rounds of the method late in the second quarter of the project period.
  • Design a robust apparatus by the end of the third quarter of the project period using commercially available therapeutic ultrasound instruments to safely and reproducibly deliver ultrasound to testes.


Our objective is to use commercially available therapeutic ultrasound instruments as the basis for a long-term, reversible male contraceptive.  The technology developed to deliver this method must be reliable enough to use in first world countries and robust enough to use in developing nations.  Drs. Tsuruta and Dayton are determining the "minimum effective dose" of ultrasound that has a contraceptive effect using an animal model and will begin to study the effects of repeated use of the method. No human clinical trials for this method are currently funded.

Measurable Objectives (using an animal model):

  1. Measure the extent of germ cell loss (efficacy).
  2. Determine the effect of multiple treatments and of their duration (safety).
  3. Determine the kinetics of returning to normal spermatogenesis.
  4. Measure the extent of reversibility (safety).


By the end of the project period we will have determined (1) the minimum effective treatment with ultrasound that results in a reversible loss of fertility and (2) whether there are any cumulative effects associated with repeated use of the method. (3) We will also have designed a prototype device for safely delivering ultrasound to the testes of men wishing to share responsibility for family planning.

Project Constraints

The first priority is to be sure that the use of ultrasound as male contraceptive is safe and effective.  Maximizing the duration of the contraceptive period increases the convenience of the method and reduces the compliance requirements of those using it. However, the method will not be acceptable if its effects are not reversible. Future studies will determine if treating for the maximum duration of effect remains compatible with the goal of reversibility. Finally, the method should be robust enough to be safely administered by trained health care volunteers.