Both compounds sit in the thymic peptide cluster, but their evidence bases and product histories differ. The useful comparison is about source material, research framing, and how cautiously storage claims should be phrased.
Thymalin and thymosin alpha-1 are frequently grouped together because both are discussed in thymic-immune research. That grouping is useful for navigation, but it should not erase the fact that the compounds are not the same molecule or evidence package.
Thymosin alpha-1 has a broader modern literature footprint, while thymalin discussion often relies more heavily on legacy or regional sources. That difference affects how confidently claims can be summarized on a public-facing page.
As with many peptide comparisons, the safe approach is to compare families and evidence tiers while avoiding blanket statements about shelf life that are not tied to a specific product or assay.
General literature anchor for thymosin alpha-1 context.
Site family hub reference.