Absorption, distribution, metabolism, and excretion (ADME) are the key biological processes for determination of a drug's pharmacokinetic parameters, which have direct impacts on efficacy and adverse drug reactions (ADRs). The chemical structures, dosage forms, and sites and routes of administration are the principal determinants of ADME profiles and consequent impacts on their efficacy and ADRs. Newly developed large biological antisense oligonucleotide (ASO) drugs have completely unique ADME that is not fully defined. ASO-based drugs are singlestranded synthetic antisense nucleic acids with diverse modes of drug actions from induction of mRNA degradation, exon skipping and restoration, and interactions with proteins. ASO drugs have a great potential to treat certain human diseases that have remained untreatable with small molecule-based drugs. The ADME of ASO drugs contributes to their unique set of ADRs and toxicity. In this review, to better understand their ADME, the ten FDA-approved ASO drugs were selected, including Fomivirsen, Pegaptanib, Mipomersen, Nusinersen, Inotersen, Defibrotide, Eteplirsen, Golodirsen, Viltolarsen, and Casimersen. A meta-analysis was conducted on their formulation, dosage, sites of administration, local and systematic distribution, metabolism, degradation, and excretion. Membrane permeabilization through endocytosis and nucleolytic degradation by endonucleases and exonucleases are major ADME features of the ASO drugs differing from small-molecule drugs. The information summarized here provides comprehensive ADME characteristics of FDA-approved ASO drugs, leading to a better understanding of their therapeutic efficacy and their potential ADRs and toxicity. Numerous knowledge gaps, particularly on cellular uptake and subcellular trafficking and distribution are identified, and future perspectives and directions are discussed.