doi:10.1101/gr.6.9.791
Some doubt its science, while others dont trust the companys marketing

Activator of: -Mercaptoethanol, 2-crystallin, 3-crystallin, E-crystallin, N-crystallin, -crystallin, 20S Proteasome 5, 3010026O09Rik, 3110003A17Rik, 4933437F05Rik, Aasdh, ACAT-3, ADAM25, AKR1A1, AKR1CL1, AKR7A3, ALDH3A2, ALG8, ALR, APNG, Arylsulfatase B, Asparagine synthetase, Blue Carrier Protein-sterile, BLVRB, C2orf34, C9orf21, COASY, COMMD7, COX19, CPXM2, CSAD, CTU1, CYB561D1, CYB561D2, CYBASC3, CYBRD1, CYHR1, CysRS, Cystinosin, Cytoplasmic CysRS, DFNB59, DHRS12, DHRS7, Dim1, DIO1, DPEP3, EAAT1, EG436008, ERIS, ERp19, ESD, ETHE1, FAM213A, Fatso, Fdx1, Gamma-glutamyltransferase (GGT), GCAT, GCL, GGL, GGT6, Glyoxalase II, Gm97, GPx-3, GPx-6, Grx1, Grx2, GRXCR1, GSTT3, H2-Dd, HEI-C, Hepatocyte Specific Antigen, hMLH3, HS3ST1, HYPB, ISCA1, IscU1, IscU2, Kell, KSP37, L2HGDH, LMBRD1, LOC150383_2210021J22Rik, MAT II, Meprin A, MGST2, MICAL1, MICAL2, Mitochondrial CysRs, MMAA, MMADHC, MsrA, MsrB2, murinoglobulin 2, NAF1, NAT-8L, NDOR1, NIPA1, NNT, Nucleoredoxin, NUDT11, NUDT18, NXNL2, ODF3B, OPLAH, OR51AA4, PAM, PANK4, PAPSS 2, PDILT, PET112L, PGD synthase, pHyde, PIWIL4, Plasmodium Aldolase, PQLC1, Prdx6b, PRODH, PROSC, PRX III, PRX2, PYROXD2, QSER1, quiescin Q6, RDH7, Rhodanese, ROPN1, Rubisco activase, S-100, SCARA3, SDR39U1, SELENBP1, Seleniumm Solution, selenocysteine lyase, Selenoprotein M marker, Selenoprotein N, Selenoprotein P, Selenoprotein R, Selenoprotein T, SLA/LP, SPLUNC3, SPTRX-3, SSSCA1, Sulfiredoxin, SVCT2, TGase2, TPRX1, Transcobalamin II, TRFP, TrxR1, TSPAN1, TUSC3, TXNDC14, TXNDC15, TXNDC16, TXNDC4, TXNDC9, TXNL1, TXNL6, Tyrosinase, UQCRHL, Urm1, UROD, UTP23, vanin-3, VAT1L, VKOR, VKORC1L1, and ZnT-1.

Studies with isolated hepatocytes would establish that human cells are less sensitive than those from mice, and that this difference is due to the relative rates of NAPQI formation
Convenient, with the most consistent (if modest) trial support, though absorption is debated and results are slower
Secretion of -lactamase requires the carboxy end of the protein