Key differences between LD50 and ED50:

LD50:

• LD50 stands for Lethal Dose 50%. 
• It indicates the median lethal dose of a substance or the lethal dose for 50% of the individuals tested and is a key measure of drug toxicity. 

ED50:

• ED50 stands for Effective Dose 50%. 
• It indicates the median effective dose of a substance or the dose required to achieve 50% of the desired response in 50% of the population. In this case, efficacy is defined as the maximum effect that a drug can cause at any given dose. The smaller the ED50, the more potent the drug.