Justin Timberlake was among those taking part in the so-called ice bucket challenge to raise awareness for Lou Gehrig's Disease, organizers said.

"We have never seen anything like this in the history of the disease," Barbara Newhouse, president and chief executive officer of The ALS Association, said in a statement Wednesday. 

Celebrities from Ethel Kennedy to Timberlake poured buckets of water over their heads in a challenge meant to raise awareness and funding for ALS.

There is only one drug approved by the U.S. Food and Drug Administration to treat ALS, or Lou Gehrig's Disease, and its effectiveness is limited.  The disease is characterized by a steady loss of control over muscle movement. This in turn leads to loss of body control and, with limited treatment options, ALS is 100 percent fatal.

Since July 29, the ALS advocacy group says it received $5.7 million in donations as part of the challenge.

See JT's video here ...