It can be stacked or alternated with clenbuterol. We usually recommend to alternate, three weeks clenbuterol with three weeks cytomel, since clenbuterol loses most of its benefits after a short period of time and using cytomel for extended time-periods will increase the risk of permanent thyroid failure.

Neither drug is terribly expensive so we see no problem in this. Some opt to use them together for 3-4 weeks, and then use an over the counter ECA stack to bridge with for an equal period of time, but we're not big fans of that. Which naturally doesn't mean its not effective, that's just a personal opinion.

Running it for three weeks, one could choose for a schedule as follows:

25/25/25/50/50/50/75/75/75/100/100/100/75/75/75/50/50/50/25/25/25 mcg/day

If taken for 4 weeks, then run each dose for 4 days, 5 weeks then each dose for 5 days and so on.
It is extremely important that the doses are tapered on and off and that a cycle never exceeds 6 weeks at the most.