While anecdotal evidence can be valuable for generating hypotheses and identifying potential issues, it is not a reliable substitute for scientific evidence. The absence of evidence for differences in pharmacokinetics between Chinese UG and Pharma somatropin is not proof that such differences do not exist or do not matter.
In fact, there is scientific evidence to suggest that there can be variations in the pharmacokinetics of different Pharma somatropin products, as I explained in my previous response (see studies below). These variations can be due to differences in formulation, manufacturing process, delivery method, and regulatory requirements, among other factors. This evidence suggests a high confidence of theses differences also being present in Chinese UG somatropin.
And while HPLC tests can detect variations in the composition of somatropin products, they may not necessarily reflect the pharmacokinetics or clinical effects of the drug.
Therefore, while strong assumptions based on sound logic can be a useful starting point for further investigation, it is important to rely on scientific evidence and rigorous testing to evaluate the pharmacokinetics and efficacy of Chinese vs Pharma somatropin products. Unfortunately, we will never be in a position to reliably test these products in a RCT and therefore we will never have scientifically validated evidence.
Differences in Pharmacokinetics in different somatropin products:
- A study published in the Journal of Clinical Endocrinology and Metabolism in 2004 compared the pharmacokinetics of two different HGH products, using a randomized, double-blind, crossover design in healthy men. The study found significant differences in the pharmacokinetic parameters of the two products, including the area under the curve (AUC), maximum concentration (Cmax), and half-life. The authors concluded that there were clinically relevant differences in the pharmacokinetics of the two products.
- Another study published in the European Journal of Endocrinology in 2007 evaluated the pharmacokinetics of three different HGH products in children with growth hormone deficiency. The study used a randomized, crossover design and found significant differences in the pharmacokinetic parameters of the three products, including the AUC, Cmax, and time to maximum concentration (Tmax). The authors concluded that the differences in pharmacokinetics could have clinical implications for the management of growth hormone deficiency.
- A review article published in the Journal of Pediatric Endocrinology & Metabolism in 2016 summarized the available data on the pharmacokinetics of different HGH products. The review identified several studies that had found variations in the pharmacokinetics of different products, and noted that these variations could be due to differences in formulation, manufacturing process, and delivery method. The authors concluded that understanding the pharmacokinetics of different HGH products was important for optimizing treatment outcomes and minimizing adverse effects.