I am afraid that the testosterone levels do go down after the Clomid is stopped. In some men, it goes down to the former level, in a few men, it can remain at a level higher than the former level.
Tongkat Ali has been proved to be quite effective in increasing testosterone levels in many men. But it has not been scientifically researched and i would not advise you to take it along with Clomid. You can try taking them separately to see which has the better effect. You should not take Tongkat Ali if you have prostate cancer, diabetes mellitus, heart disease, kidney disease, liver disease, or sleep apnea.
The dose of Tongkat Ali is 1,000 to 1,500 mg per day. It should be taken on a cycle of 6 days on, followed by 3 days off or on-cycle of 10 days, followed by 5 days off.