There is nothing in the United States Constitution about assisted suicide. It is up to the states to make assisted suicide legal or illegal. This is shown by 3 states legalizing assisted suicide while the others hold on to laws making it illegal

Assisted suicide is when the person who is committing suicide is assisted by another person, who will provide the implements of the suicide and/or instructions, and who knows that the person is about to commit suicide. Normally the suicide patient will follow instructions, which will induce his death.

Assisted suicide is legal in Oregon, Washington, and Montana.

Assisted suicide means that someone is helping someone commit suicide. Therefore it's any of the usual ways to commit suicide, just with someone helping.

Strato