I hesitate back and forth whether to say this or not because I don't want people to get the wrong idea.
However, I have run methylated orals for 14+ weeks straight... With liver support and lipid support. Mildly elevated liver values and lipids were "okay".
I don't suggest doing this because you aren't guaranteed to have a mild reaction like me.
If you are going to run for longer than 4 weeks, just make sure you get checked out. Please be cautious and don't follow my example because you think it is safe for you.
I do, however know that different compounds can have different effects on your liver. I ran 2 weeks low/moderate dose of DNP in the past... About 7-8 years ago. Among other things severely out of range, were my liver values... Very high. So I know my liver isn't impervious to damage. Values recovered to normal range within 6 weeks. Thank God.
Any time you take methylated compounds please do take liver support and please do get tested. If values get out of acceptable range, discontinue use immediately.