@“unclecurley” is spot on. When dosing e.g. an oil in hundreds of milligrams per ml, any UGL should be able to get it right. A microgram is such a small unit of measure it’s practically microscopic, and T3 in particular is an extremely powerful hormone - you can easily, easily be off by 2x or 3x with disastrous results. Pharma is the way to go.
Only other thought - it’s worth getting thyroid bloodwork anyway, and it’s generally pretty affordable through anti-aging / men’s health clinics. My thyroid baseline was borderline-low so I was able to get a script for 3 grains of armour thyroid (mix of T3/T4, but roughly equivalent to ~50mcg T3). The fact that you can generally get a TRT script as well (which helps with muscle catabolism) is a big bonus.
Having pharm-grade levels for replacement (hell, if we’re being honest, even a little bit of enhancement) is great. Then you can go UGL for your blast needs.