This is truth, dimer and aggregates just decrease the amount of active GH. That's why I inject anyway even if I see a few floaters. Fortunately I'm not an atopic person and have had no issues with allergic reactions... except for MOTs-C which always causes some transient redness and itching, but that seems almost universal and way to validate it is in fact MOTS-C; not surprising as it is a mitochondrial-only peptide not normally visible to the immune system.
First GH I used was Meditropie black which would cause pretty bad CTS symptoms at 4 iu. I switched to K4L which did not, but figured its potency was overrated. Now using Opti, slowly worked my way up to 7.5iu which gives me a couple minutes of transient, slightly annoying CTS that goes away rapidly - so figure that's the ceiling dose for me.