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Underdog Male Fertility Cooling Kit on amazon.com

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Sitting Damages Sperm

Graph showing lower sperm count and decreased motility from testicular overheat.

Introducing The Underdog

The Underdog fertility cooling ice pack in sleeve.

The Underdog Prevents Overheating

Graph showing results of cooling testicles for improving sperm count using Underdog ice pack.


Easy to Use

-Small and discreet

-Slips easily between the seat and pants

-No special underwear

-No condensation

Improve Fertility Naturally

-Very mild & gentle cooling

-Non-invasive and no-risk

-Use before natural conception or IVF to improve the odds

Soft and Comfortable

-Comfortable padded sleeve

-Ergonomic wedge shape

-Fits all body types

Better Sperm, Better Outcomes.

Are you ready to get started?


Promising enough that we are offering our men the option of using these devices ‎as a part of their therapy for infertility.

Dr. K. J.

Healthy sperm are very sensitive to overheating. The Underdog keeps the testes at the perfect temperature. Wonderful and discrete. Highly recommended.

Dr. C. L.

Quality build and packaging. The ice pack is comfortable enough to use for a few hours straight while keeping its "cool", and inconspicuous enough for the office.


It cools down my balls and raises sperm counts. Would highly recommend to those who want to conceive.


Pretty impressed with this product. First, it comes with two ice packs which is great for a long day. Next, it feels very comfortable when using. Temperature is perfect. Not too cold or hot.


Expert Recommendation

Fertility expert Dr. Charlene Lincoln recommends using The Underdog to improve sperm quality.

The Underdog Mission

Underdog Fertility was founded by three professionals who care deeply about helping others start a family.  

With the help of our medical advisory team, we're on a mission to create practical tools that improve men's health. 

Life is short, so let's get started!

The Underdog is protected by US and international utility patents pending.

Underdog, The Underdog, Underdog Fertility and the Dogface Logo are trademarks of Underdog Fertility. 

Note: The Underdog is a general wellness device, and is not intended for use in the the cure, mitigation, treatment, or prevention of underlying disease or medical conditions.