What I have is one tube good for a horse of 1250lbs.
Just do the math to correlate to your weight. From what I have read is you take 2 doses three days apart and that will give you protection.
Don’t take my word, though. Double check it with your own due diligence.
Start here for calculating how much horse ivermectin to take.
Good instructions
Gas_dr has made some “educational” posts about invermectin and dosage elsewhere in FR. Just do a search on his username.