Final answer:
Fractionated doses are less lethal due to the short half-life of peptides and reduced accumulation in tissues.
Step-by-step explanation:
Fractionated doses are less lethal because of their short half-life and the reduced accumulation of peptides in tissues. Fractionated doses reduce the risk of complications caused by metabolites. Peptides with short half-lives are quickly eliminated from the body, minimizing their toxic effects.