I switched back to the other GH and the thirst and frequent urination went away very quickly. Switched back again, and it's back. I wasn't expecting any of this, so I highly doubt it's psychosomatic. Any other possible explanations? I've been on Retatrutide at 3mg/week throughout all of this.
I don't think it's psychosomatic either.
I think if you're using the same dose with each. one is more bioactive than the other, and I bet head to head IGF after two weeks on each would prove this.
Most people don't know what IU really means. It's not a weight. It's a measure of rHGH activity.
The "standard" is 3iu per mg of rHGH.
Pharma takes a mg of their rHGH, puts it in a vial with specially grown cells that have HGH receptors. Then they measure how much IGF is produced to get "iu of bioactivity".
It has to be between 2.6iu and 3.1iu to meet FDA standard. As long as it's between these two numbers they are allowed to call it 3iu/mg on the box.
These days modern production is so good they sometimes get above 3.1iu/mg, and have to dilute it to lower bioactivity.
The reason it varies is that while rHGH can be 99% pure on HPLC, there are many types of rHGH "defects" that can't. be detected in purity tests, and the only true measure of how well it will attach to receptors is with a bioactivity test.
Unlike pharma, UGL rHGH doesn't get thrown out if it's out of bioactivity range. it's not even checked. It could be 2.1iu/mg or 4iu/mg. It all gets called 3iu/mg.
So now you know. Two batches of UGL rHGH, same purity, same dose, can have significantly different levels of bioactivity.
The one that's more bioactive will cause more rHGH effects, both desirable, and sides.