# Thymosin beta-4 & TB-500 — Identify the Molecule

Peptides in 2 · Repair, Recovery & Tissue Health · Publication edition

Evidence checked October 15, 2026. Single Tom narrator at normal synthesis speed; no time-stretching. The established series screens open and close the film, and the signature includes “World Peptide Foundation. Peptides in 2. Every experience matters.” No numbered film label appears on-screen.

## Distinct editorial question

Full-length thymosin beta-4 and a related fragment must not silently share an evidence claim. The film follows molecular characterization into a condition-specific eye-formulation study, then asks whether that result can transfer to a different preparation and body tissue.

## Source boundaries

- Esposito and colleagues identified an acetylated seven-residue fragment in material sold as TB-500. This is a characterization result, not a clinical-benefit study.
- FDA’s 2026 evaluation describes inconsistent common-name use and distinguishes the fragment from full-length thymosin beta-4. Related names do not establish equivalent identity or activity.
- The RGN-259 eye study enrolled 18 participants. The four-week primary comparison reported healing in 6/10 versus 1/8, p=0.0656 against the planned 0.05 threshold. Later follow-up favored treatment. The trial stopped early because of slow recruitment and involved developer-affiliated authors. Small-sample uncertainty and condition/formulation specificity remain explicit; missing a threshold is not proof of no benefit.

## Original sources

1. Esposito S et al. (2012). Analytical identification of the acetylated 17–23 fragment in TB-500. [PMID 22962027](https://pubmed.ncbi.nlm.nih.gov/22962027/). DOI: 10.1002/dta.1402.
2. FDA (2026). Evaluation of TB-500-related bulk drug substances. [Official document](https://www.fda.gov/media/193349/download). Molecular identity/common naming and distinction from the 43-residue parent peptide are discussed in the evaluation.
3. Sosne G et al. (2023). RGN-259 randomized neurotrophic-keratopathy study. [Primary publication](https://www.mdpi.com/1422-0067/24/1/554). DOI: 10.3390/ijms24010554. [PMID 36613994](https://pubmed.ncbi.nlm.nih.gov/36613994/).

## Production and transparency

Ten original, newly generated content images each appear in one continuous passage. None is reused from BPC-157. The established title artwork is the sole intentional repeat. Native charts use the published counts and distinguish the primary endpoint.

Artwork prompts, timing, transcript, recognition-assisted captions, and render code are included. No independent scientific review or complete manual caption review is claimed. References and study limitations accompany the published episode.

## Rebuild

Use Python with Pillow/NumPy, ffmpeg, and Montserrat. Run `python3 render.py`. Recognition dependencies and cached models are not included. The renderer consumes the included narration and paragraph-alignment data.