Hi there ~
You have not mentioned what weight loss supplement
you are taking, however there are many which can cause constipation
as a side effect. If you are having a clear correlation between starting the medication and having constipation it probably is related and I would like for you to stop taking the weight loss medication. If your medication was effective in making you lose weight, I recommend that you go in for surgery for hemorrhoids and start yourself on a diet regimen that includes a lot of fibre and fluids. I hope you also consult a nutritionist in that case. I hope this helps.
Good luck and take care!