I agree with Jim, Jano and Chest
If it's one of the cheap "Generic" GH products causing welts at the site injection
everytime, then its possibly/probably a higher amount of endotoxins present than what's normally allowed in legit PHARMA GH ( endotoxin levels to 0.5 EU/µg or less)
A final "purifying process" in manufacturing the Synthetic Protein (HGH) is skipped or not done well to provide a "Cheap Chinese Generic GH Product"
Endotoxins (lipopolysaccharides, LPS) are major contaminants found in commercially available proteins or biologically active substances. LPS are highly potent immune stimulators able to cause side effects
Purification very often represents the most time consuming and cost intensive step of the whole production process. Therefore optimization of the downstream process is essential in order to achieve time and cost efficiency (3). Generally, high LPS concentrations can be reduced to about 100 EU/mL without special treatment, but many applications require an even lower-limit value as described within the pharmacopoeia — e.g., 5 endotoxin units (1 EU ≈ 100 pg) per kilogram of body weight per hour for intravenous applications.
Endotoxin Testing Analysis and Removal - Bio-Synthesis, Inc.
Bacteria pyrogen such as endotoxins, also called lipopolysaccharides (LPS), are major contaminants found in commercially available proteins or biologically active substances. This bacterial endotoxin is a potent stimulator of the mammalian immune system in vivo, and it may decrease tissue culture cell viability and inhibit transfection efficiency in vitro.
Also, bacterial residue in low grade Somatropin or Somatrem (192) can cause reactions
(I agree with jano that 192 is no longer common on the black market)
Painful red welts on injection spot can be caused by low quality growth hormone which contain too much bacterial residue (Endotoxins ((lipopolysaccharides, LPS)). This can lead to serious problems where the body could eventually develop resistance (Protein Immunogenicity) even against its own naturally produced growth hormone. (Immune response similar to Somatrem)
If the welts appear after every injection and persist for a day or two, then you should discontinue use
Injecting IM (BroScience) to elimate the reaction isn't best IMO