system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] Why doesn't the US military mass produce super soldiers like Captain America?

Don't they still have the recipe for the serum?
gpt
Nope. The secret to the Serum was lost when Dr Erskine was murdered.

Various attempts to re-create the process were made over the years, with varying levels of effectiveness, but none were truly successful.