You wont get a heroin like high. but a more subtle high is possible, depending on the quality of your product . Doesn't matter what the vendor claims it to be . Just google kratom dosage .
Does nobody understand how to use search engines ?
Problem with Kratom is it varies a lot between strains. The only real way to gauge dose is to try and find people who have already tried it and see what doses they used.
Not sure if this still goes on, but I remember a year or two back some of the ultra-potent Kratom strains were found to contain o-des-tramadol.