Thymosin Alpha-1 Side Effects: What Studies and Users Report
What FDA labels and clinical studies report for Thymosin Alpha-1, how strong that evidence is, and what is still unknown.
Side effects reported in studies
Side effects reported in published studies, strongest design first. Frequencies are quoted as the source gives them; animal results are labelled.
| Side effect | How common | Study type | Source |
|---|---|---|---|
| Serious adverse events | 7 per group | Human RCTn = 25 | Hepatology international 2009, PMID 19669251 |
What is not known
- How common each effect is at the doses people use outside of studies.
- Effects that take longer to appear than the length of the published studies.
- How Thymosin Alpha-1 interacts with other medicines and supplements.
- Whether research-grade products, which are not checked by the FDA, behave like the material used in studies.
When to get medical help
Get urgent care for: trouble breathing, swelling of the face or throat, a widespread rash, severe or lasting stomach pain, fainting, or an injection site that becomes hot, red and spreading.
This is not a complete list. A doctor or pharmacist can help you judge whether a symptom is related.
Common questions
What are the side effects of Thymosin Alpha-1?
Studies we summarise reported serious adverse events. The table on this page gives how often each happened and links each source.
Is Thymosin Alpha-1 safe?
Thymosin Alpha-1 has an FDA-approved label that lists its known risks. That label covers the approved product used as prescribed, not compounded or research-chemical versions.
More on Thymosin Alpha-1
Sources
- 1A randomized controlled trial of thymalfasin plus transarterial chemoembolization for unresectable hepatocellular carcinoma.Hepatology international · 2009PMID 19669251Accessed 2 Oct 2026
Found an error? Report a correction.