This app has been a tremendous help.
This app has been a tremendous help.
By Quin Q.
Response from Fat Scientist· Aug 3, 2026
So happy to hear it, thanks Quin.
Monday, November 2, 2026 · Customer reviews of US businesses
The Fair Hearing score
Excellent
129 reviews
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Fat Scientist is a free online resource built for people using GLP-1 medications like tirzepatide (Mounjaro, Zepbound) and semaglutide (Ozempic, Wegovy). We specialize in tools and educational content for users of compounded versions of these medications, which come in multi-dose vials and require precise dosage calculations. Our suite of calculators helps users convert prescribed milligram doses into exact syringe units based on their specific vial concentration, calculate split doses for improved tolerability, estimate medication costs, and plan their treatment timelines. Every calculator is free, requires no account, and works on any device. We built Fat Scientist because compounded GLP-1 medications present a unique challenge. Unlike brand-name auto-injectors with pre-measured doses, compounded vials require users to do math that directly impacts their safety. A wrong calculation means injecting too much or too little medication. We believe nobody should have to guess when it comes to their health, and the tools to get it right should be accessible to everyone. Beyond calculators, Fat Scientist provides guides on topics like reading vial labels, understanding concentration values, proper injection technique, and navigating the differences between brand-name and compounded medications. Our FAQ library addresses the most common questions we see in GLP-1 communities, written in plain language without medical jargon. Fat Scientist is operated by Productist LLC. We are not a pharmacy, we do not sell medications, and we are not a substitute for medical advice. Our mission is purely informational — giving GLP-1 users the tools and knowledge to use their medications safely and confidently. We are funded by voluntary donations from our users, not advertising or affiliate deals, so our recommendations are never influenced by commercial interests. Whether you are just starting your GLP-1 journey or adjusting an existing regimen, Fat Scientist is here to help you get the nu
Fat Scientist (fatscientist.com) has 129 customer reviews on The Fair Hearing, with an average rating of 5.0 out of 5.
129 approved reviews, newest moderated first
This app has been a tremendous help.
By Quin Q.
Response from Fat Scientist· Aug 3, 2026
So happy to hear it, thanks Quin.
This is an exceedingly helpful website for understanding dosing when using tirzepatide vials. thanks!
By Laura
Response from Fat Scientist· Aug 3, 2026
Thank you Laura, so glad to hear it!
Use this tool and recommend this tool ALL the time. Gives you what you need in extremely user friendly format.
By SWatogaM
I literally use this app every day to plan and double/triple check my tirzepatide doses! Love all that it offers and that it does all my "mathing" for me! It has helped me tremendously on my weight loss journey! Thank you!!
By Sara L.
Very helpful tools!
By BriGette
This is an amazing resource. Thank you for helping us be empowered and accurate.
By Tricia
This is such a helpful resource for anyone starting out on the GLP-1 journey, and it's just as much a necessary tool for more seasoned patients too! I think I've double checked myself w/ FatScientist everytime I've needed to reconstitute a vial of tirz. and I imagine I'll continue to do so. The calculator is easy to use, & the site has easy to follow recommendations and answers to FAQs. I recently discovered the new link for info on Retatrutide, and look forward to using that as well if I end up switching over to that newer GLP-1. Thanks for this easy to use site!
By Megan H.
Response from Fat Scientist· Aug 3, 2026
Megan, you rock! Thanks so much for the kind words, it means a lot.
I would have never been confident in my choices without this calculator.
By Bishop D.
Response from Fat Scientist· Aug 3, 2026
That's one of our main goals -- helping people feel confident and comfortable