Well, Kevorkian did get sent to prison, but his was an extreme case; he publicized his activities & was a frank provocation. Even so, it took a long time for the enemy to wangle a conviction.

People are bound to have mixed feelings about assisted suicide, and because of religious agitation it is a party question, so the present situation is that it is hard to make it legal, but also hard to punish anyone for it. The result is that with luck you may well end up with a circumspect doctor who can do what you want, but there is also a considerable risk of ending your life horribly imprisoned.

Here is how it worked out in England in 1936, when the poet A. E. Housman was on his deathbed. His doctor recalled:

You know how silent and reserved he always was; but this time he talked quite a lot and very affectionately. He held my hand for nearly half an hour. "You have been a good friend to me," he said; "I know you have brought me here so that I may not commit suicide, and I know that you may not help me to it more than the law allows. But I do ask you not to let me have any more unnecessary suffering than you can help." I told him that he should not suffer any more; and from that time on he did not. Then, to cheer him up just before I left, I told him a thoroughly naughty story. He was very weak, but he threw his head back on the pillow laughing heartily. "Yes, that's a good one," he said, "and to-morrow I shall be telling it again on the Golden Floor."

-- Bless that doctor! We are not even told his name.