Tesa - How much can I reconstitute at once?

Assuming a daily dose that uses 10 mg vials over five days on, I would not mix more than two at a time and would actually prefer to do just one. After mixing, potency declines gradually at first then faster from week two onward, though it may still be usable. By week three the loss can reach ten percent or higher. Keeping it fresh seems safest, and the opened mixing solution will last for later weeks anyway.

Pairs are what I select and they last me ten days altogether.

I don't have solid evidence either, and you're probably correct. I pieced this together from limited information and online lookups. Based on some investigations with an AI tool, the approved product mixed using a preservative solution can stay at normal indoor temperatures and gets thrown out after a week once prepared. Earlier versions without that preservative need to be administered right away. This suggests the companies are aware of how effectiveness drops over time. Additional research on similar compounds with the same basic structure indicated major breakdown after two weeks in samples, resulting in reduced ability to stimulate growth hormone release because of changes in the molecule. The speed of this process remains guesswork based on personal stories, yet it seems reasonable that newer preparations work better and there's likely some reduction in strength daily after preparation. The exact amount lost and whether it becomes significant inside a month isn't clear, but it convinces me it's better not to prepare multiple containers in advance.