Erythromycin estolate is a semi-synthetic macrolide antibiotic, the lauryl sulfate salt of erythromycin propionate. It exhibits broad-spectrum activity against Gram-positive bacteria and some Gram-negative organisms.

In laboratory applications, it is used as a reference standard for antimicrobial susceptibility testing, microbiological media supplementation, pharmaceutical analysis, and research on bacterial infections, including respiratory, skin, STI models, pertussis, leptospirosis, and otitis media.

Available as a high-purity (99-100%) solid (GR grade) with infrared spectrum conforming to structure, suitable for precise experimental use. Not for human or veterinary therapeutic use.