We’re warning you, if you’re not a lawyer, then you’ll find this post very boring. It’s mostly a citator – a compilation of relevant precedents on a particular topic, the learned intermediary rule. Lawyers, who have to deal in legal precedent on a daily basis, eat this kind of thing up (it saves looking the damn stuff up on our own). Everyone else probably finds is as interesting as reading a telephone book.
There, you have been warned.
In State ex rel. Johnson & Johnson Corp. v. Karl, 647 S.E.2d 899, 906-914 (W. Va. Jun. 27, 2007), the court rejected the learned intermediary rule.  Now Karl has been overturned by statute.  There has been some confusion about which jurisdictions have adopted the learned intermediary rule. Various courts have used different numbers of states, from a low of 22 (in Karl) to a high of 48. We thought we’d try to fix that situation, because we think every state has now has precedent adopting the rule. Here’s our list, broken into categories:

Jurisdictions In Which the Legislature or Highest Court Has Adopted the Rule in Prescription Medical Product Cases (36 + DC):

Alabama: Blackburn v. Shire U.S., Inc., ___ So.3d ___, 2022 WL 4588887, at *4-5 (Ala. Sept. 30, 2022); Wyeth, Inc. v. Weeks, 159 So.3d 649, 672-74 (Ala. 2014); Walls v. Alpharma USPD, 887 So.2d 881, 883 (Ala. 2004); Morguson v. 3M Corp., 857 So.2d 796. 801-02 (Ala. 2003); Stone v. Smith, Kline & French Laboratories, 447 So.2d 1301, 1305 (Ala. 1984).
Alaska: Shanks v. Upjohn Co., 835 P.2d 1189, 1200 & n.17 (Alaska 1992).
Arizona: Conklin v. Medtronic, Inc., 431 P.3d 571, 577 (Ariz. 2018); Watts v. Medicis Pharmaceutical Corp., 365 P.3d 944, 948-50 (Ariz. 2016).
Arkansas: West v. Searle & Co., 806 S.W.2d 608, 613 (Ark. 1991).
California: Himes v. Somatics, LLC, 549 P.3d 916, 922-25 (Cal. 2024); Webb v. Special Electric Co., 370 P.3d 1022,1034 n.10 (Cal. 2016); Carlin v. Superior Court, 920 P.2d 1347, 1354 (Cal. 1996); Brown v. Superior Court, 751 P.2d 470, 477 n.9 (Cal. 1988); Stevens v. Parke, Davis & Co., 507 P.2d 653, 660 (Cal. 1973).
Connecticut: Hurley v. Heart Physicians, P.C., 898 A.2d 777, 783-84 (Conn. 2006); Vitanza v. Upjohn Co., 778 A.2d 829, 836-38 (Conn. 2001).
Delaware: Lacy v. G.D. Searle & Co., 567 A.2d 398, 400-01 (Del. 1989).
District of Columbia: Mampe v. Ayerst Laboratories, 548 A.2d 798, 801 & n.6 (D.C. 1988).
Florida: E.R. Squibb & Sons, Inc. v. Farnes, 697 So.2d 825, 827 (Fla. 1997); Upjohn Co. v. MacMurdo, 562 So.2d 680, 683 (Fla. 1990); Felix v. Hoffmann-LaRoche, Inc., 540 So.2d 102, 104 (Fla. 1989).  The Florida Supreme Court extended the rule to non-prescription products (what most states call “sophisticated purchaser”) in Aubin v. Union Carbide Corp., 177 So.3d 489, 516 (Fla. 2015).
Georgia: McCombs v. Synthes, 587 S.E.2d 594, 595 (Ga. 2003).
Hawaii: Craft v. Peebles, 893 P.2d 138, 155 (Hawaii 1995).
Illinois: Happel v. Wal-Mart Stores, Inc., 766 N.E.2d 1118, 1127 (Ill. 2002); Hansen v. Baxter Healthcare Corp., 764 N.E.2d 35, 42 (Ill. 2002); Martin v. Ortho Pharmaceutical Corp., 661 N.E.2d 352, 354 (Ill. 1996); Kirk v. Michael Reese Hospital & Medical Center, 513 N.E.2d 387, 393 (Ill. 1987).
Kansas: Savina v. Sterling Drug, Inc., 795 P.2d 915, 928 (Kan. 1990); Humes v. Clinton, 792 P.2d 1032, 1039-40 (Kan. 1990); Tetuan v. A.H. Robins Co., 738 P.2d 1210, 1227-28 (Kan. 1987); Johnson v. American Cyanamid Co., 718 P.2d 1318, 1324 (Kan. 1986); Wooderson v. Ortho Pharmaceutical Corp., 681 P.2d 1038, 1052 (Kan. 1984).
Kentucky: Larkin v. Pfizer, Inc., 153 S.W.3d 758, 761 (Ky. 2004).
Maryland: Rite Aid Corp. v. Levy-Gray, 894 A.2d 563, 577 (Md. 2006); Nolan v. Dillon, 276 A.2d 36, 40 (Md. 1971).
Massachusetts: Cottam v. CVS Pharmacy, 764 N.E.2d 814, 820 (Mass. 2002); MacDonald v. Ortho Pharmaceutical Corp., 475 N.E.2d 65, 68 (Mass. 1985).
Michigan: Smith v. E.R. Squibb & Sons, Inc., 273 N.W.2d 476, 479 (Mich. 1979). To be fair, the statement in Smith was characterized as “dictum” in In re Certified Questions, 358 N.W.2d 873, 877 (Mich. 1984), but it has been followed by lower Michigan courts. E.g., Mowery v. Crittenton Hospital, 400 N.W.2d 633, 637 (Mich. App. 1986).
Minnesota: Mulder v. Parke Davis & Co., 181 N.W.2d 882, 885 n.1 (Minn. 1970).
Mississippi: Miss. Code §11-1-63(c)(ii); Janssen Pharmaceutica, Inc. v. Bailey, 878 So.2d 31, 57 (Miss. 2004); Moore v. Memorial Hospital, 825 So.2d 658, 664 (Miss. 2002); Bennett v. Madakasira, 821 So.2d 794, 804 (Miss. 2002); Wyeth Laboratories, Inc. v. Fortenberry, 530 So.2d 688, 691-92 (Miss. 1988).
Missouri: Krug v. Sterling Drug, Inc., 416 S.W.2d 143, 146-47 (Mo. 1967).
Montana:  Stevens v. Novartis Pharmaceuticals Corp., 247 P.3d 244, 259 (Mont. 2010); Hill v. Squibb & Sons, 592 P.2d 1383, 1387-88 (Mont. 1979).
Nebraska: Freeman v. Hoffman-La Roche, Inc., 618 N.W.2d 827, 841-42 (Neb. 2000).
Nevada:  Klasch v. Walgreen Co., 264 P.3d 1155, 1159 (Nev. 2011); Allison v. Merck & Co., 878 P.2d 948, 958 n.16 (Nev. 1994) (plurality op.), 969 (dissent also following learned intermediary rule).
New Jersey: N.J. Stat. §2A:58C-4; In re Accutane Litigation, 194 A.3d 503, 524 (N.J. 2018); Perez v. Wyeth Laboratories, Inc., 734 A.2d 1245, 1257 (N.J. 1999); Niemiera v. Schneider, 555 A.2d 1112, 1117 (N.J. 1989).
New York: Spensieri v. Lasky, 723 N.E.2d 544, 549 (N.Y. 1999); Martin v. Hacker, 628 N.E.2d 1308, 1311 (N.Y. 1993).
North Carolina:  N.C. Gen. Stat. §99B-5(c).
Ohio: Ohio Rev. Code §2307.76(c); Howland v. Purdue Pharma, L.P., 821 N.E.2d 141, 146 (Ohio 2004); Vaccariello v. Smith & Nephew Richards, Inc., 763 N.E.2d 160, 164 (Ohio 2002); Wagner v. Roche Laboratories, 671 N.E.2d 252, 256 (Ohio 1996); Tracy v. Merrell Dow Pharmaceuticals, Inc., 569 N.E.2d 875, 876, 878 (Ohio 1991); White v. Wyeth Laboratories, Inc., 533 N.E.2d 748, 755 (Ohio 1988); Seley v. G.D. Searle & Co., 423 N.E.2d 831, 834, 836-37 (Ohio 1981).
Oklahoma: Edwards v. Basel Pharmaceuticals, 933 P.2d 298, 300-01 (Okla. 1997); Tansy v. Dacomed Corp., 890 P.2d 881, 886 (Okla. 1994); McKee v. Moore, 648 P.2d 21, 24 (Okla. 1982); Cunningham v. Charles Pfizer & Co., 532 P.2d 1377, 1381 (Okla. 1974).
Oregon: Oksenholt v. Lederle Laboratories, 656 P.2d 293, 296-97 (Or. 1982); Vaughn v. G.D. Searle & Co., 536 P.2d 1247, 1247-48 (Or. 1975); McEwen v. Ortho Pharmaceutical Corp., 528 P.2d 522, 528 (Or. 1974). See Griffith v. Blatt, 51 P.3d 1256, 1262 (Or. 2002) (product liability statute limits learned intermediary rule in actions against intermediate sellers in strict liability).
Pennsylvania: Lance v. Wyeth, 85 A.3d 434, 438 n.6 (Pa. 2014); Coyle v. Richardson-Merrell, Inc., 584 A.2d 1383, 1385 (Pa. 1991); Baldino v. Castagna, 478 A.2d 807, 812 (Pa. 1984); Incollingo v. Ewing, 282 A.2d 206, 220 & n.8 (Pa. 1971).
Tennessee: Pittman v. Upjohn Co., 890 S.W.2d 425, 429 (Tenn. 1994).
Texas: Centocor, Inc. v. Hamilton, 372 S.W.3d 140, 154-59 (Tex. 2012).
Utah: Feasel v. Tracker Marine LLC, 496 P.3d 95, 103 & n.46 (Utah 2021); Schaerrer v Stewart’s Plaza Pharmacy, Inc., 79 P.3d 922, 928-29 (Utah 2003); Barson v. E.R. Squibb & Sons, Inc., 682 P.2d 832, 835 (Utah 1984).
Virginia: Pfizer, Inc. v. Jones, 272 S.E.2d 43, 44 (Va. 1980).
Washington: Rublee v. Carrier Corp., 428 P.3d 1207, 1216-17 (Wash. 2018); Washington State Physicians Insurance Exchange & Ass’n v. Fisons Corp., 858 P.2d 1054, 1061 (Wash. 1993); Rogers v. Miles Laboratories, Inc., 802 P.2d 1346, 1353 (Wash. 1991); McKee v. American Home Products Corp., 782 P.2d 1045, 1149-50 (Wash. 1989); Terhune v. A.H. Robbins Co., 577 P.2d 975, 978 (Wash. 1978).
West Virginia:  W. Va. Stat. §55-7-30 (effective May 17, 2016).  See McNair v. Johnson & Johnson, 818 S.E.2d 852, 865-66 (W. Va. 2018) (recognizing codification of learned intermediary rule).
Wyoming:  Rohde v. Smiths Medical, 165 P.3d 433, 438 (Wyo. 2007).

Jurisdictions In Which the Highest Court Has Adopted the Rule in a Non-Prescription Medical Product Case (2):

Idaho: Sliman v. Aluminum Co. of America, 731 P.2d 1267, 1270 (Idaho 1986).
South Carolina: Madison v. American Home Products Corp., 595 S.E.2d 493, 496 (S.C. 2004).

Jurisdictions In Which an Intermediate Appellate Court Has Adopted the Rule in Prescription Medical Product Cases (4):

Colorado: O’Connell v. Biomet, Inc., 250 P.3d 1278, 1281-82 (Colo. App. 2010); Hamilton v. Hardy, 549 P.2d 1099, 1110 (Colo. App. 1976).
Indiana: Ortho Pharmaceutical Corp. v. Chapman, 388 N.E.2d 541, 548-59 (Ind. App. 1979).
Louisiana: Kampmann v. Mason, 921 So.2d 1093, 1094 (La. App. 2006); David v. Our Lady of Lake Hospital, Inc., 857 So. 2d 529, 532 (La. App. 2003); Brown v. Glaxo, Inc., 790 So.2d 35, 38 (La. App. 2000); Calhoun v. Hoffman-LaRoche, Inc., 768 So.2d 57, 61 (La. App. 2000); Mikell v. Hoffman-LaRoche, Inc., 649 So.2d 75, 79-80 (La. App. 1994); Rohto v. Ribando, 504 So.2d 1119, 1123 (La. App. 1987); Kinney v. Hutchinson, 468 So.2d 714, 717 (La. App. 1985); Cobb v. Syntex Laboratories, Inc., 444 So.2d 203, 205-06 (La. App. 1983).
New Mexico: Silva v. SmithKlineBeecham Corp., 2013 WL 4516160, at *2-3 (N.M. App. Feb. 7, 2013); Serna v. Roche Laboratories, Division of Hoffman-LaRoche, Inc., 684 P.2d 1187, 1189 (N.M. App. 1984); Jones v. Minnesota Mining & Manufacturing Co., 669 P.2d 744, 748 (N.M. App. 1983); Perfetti v. McGahn Medical, 662 P.2d 646, 650 (N.M. App. 1983); Richards v. Upjohn Co., 625 P.2d 1192, 1195 (N.M. App. 1980); Hines v. St. Joseph’s Hospital, 527 P.2d 1075, 1077 (N.M. App. 1974).

Jurisdictions In Which Federal Courts Have Predicted the Adoption of the Rule in Prescription Medical Product Cases Where the State Courts Are Silent (11):

Note: this category repeats South Carolina and Idaho, which have high court precedent in non-medical product cases.
Idaho:  In re Zimmer M/L Taper Hip Prosthesis or M/L Taper Hip Prosthesis with Kinectiv Technology & Versys Femoral Head Products Liability Litigation, 2021 WL 3475681, at *12 (S.D.N.Y. Aug. 6, 2021) (applying Idaho law).
Iowa: Petty v. United States, 740 F.2d 1428, 1440 (8th Cir. 1984); Kelly v. Ethicon, Inc., 2020 WL 4572348, at *4 (N.D. Iowa Aug. 7, 2020), reconsideration denied, 2020 WL 6120155 (N.D. Iowa Oct. 16, 2020); Wessels v. Biomet Orthopedics, LLC, 2020 WL 3421478, at *14 (N.D. Iowa June 22, 2020); Nicholson v. Biomet, Inc., 2020 WL 3399899, at *15 (N.D. Iowa March 6, 2020); Willet v. Johnson & Johnson, 2019 WL 7500524, at *2 (S.D. Iowa Sept. 30, 2019); Gilliland v. Novartis Pharmaceuticals Corp., 34 F. Supp.3d 960, 969 (S.D. Iowa 2014); Madsen v. American Home Products Corp., 477 F. Supp.2d 1025, 1033-34 (E.D. Mo. 2007).
Maine: Violette v. Smith & Nephew Dyonics, Inc., 62 F.3d 8, 13 (1st Cir. 1995); Doe v. Solvay Pharmaceuticals, Inc., 350 F. Supp.2d 257, 270-71 (D. Me. 2004), aff’d, 153 Fed. Appx. 1 (1st Cir. 2005); Herzog v. Arthrocare Corp., 2003 WL 1785795, at *8 (D. Me. March 21, 2003).
New Hampshire: Brochu v. Ortho Pharmaceutical Corp., 642 F.2d 652, 656 (1st Cir. 1981); McCue v. Norwich Pharmacal Co., 453 F.2d 1033, 1035 (1st Cir. 1972); Nelson v. Dalkon Shield Claimants Trust, 1994 WL 255392, at *4 (D.N.H. Jun. 8, 1994); Dupre v. G.D. Searle & Co., 1987 WL 158107, at *4 (D.N.H. Apr. 28, 1987).
North Dakota: Ehlis v. Shire Richwood, Inc., 367 F.3d 1013, 1017 (8th Cir. 2004); Harris v. McNeil Pharmaceutical, 2000 WL 33339657, at *4 n.4 (D.N.D. Sept. 5, 2000).
Puerto Rico: Guevara v. Dorsey Laboratories, Division of Sandoz, Inc., 845 F.2d 364, 366 (1st Cir. 1988); Pierluisi v. E.R. Squibb & Sons, Inc., 440 F. Supp. 691, 694-95 (D.P.R. 1977).
Rhode Island:  Greaves v. Eli Lilly & Co., 503 F. Appx. 70, 71-72 (2d Cir. 2012); Franks v. Coopersurgical, Inc., 2024 WL 1109055, at *17 (D.R.I. March 14, 2024); Costa v. Johnson & Johnson, 2023 WL 2662903, at *3 (D.R.I. March 28, 2023); Hogan v. Novartis Pharmaceuticals Corp., 2011 WL 1533467, at *9-10 (E.D.N.Y. April 23, 2011).
South Carolina: Odom v. G.D. Searle & Co., 979 F.2d 1001, 1004 (4th Cir. 1992); Brooks v. Medtronic Inc., 750 F.2d 1227, 1231 (4th Cir. 1984); Jones v. Danek Medical, Inc., 1999 WL 1133272, at *7 (D.S.C. Oct. 12, 1999); Pleasant v. Dow Corning Corp., 1993 WL 1156110, at *6 (D.S.C. Jan. 7, 1993); Purnell v. United States, 1987 WL 11212, at *1 (E.D. Pa. May 21, 1987).
South Dakota: Schilf v. Eli Lilly & Co., 2010 WL 4024922 (D.S.D. Oct. 13, 2010); McElhaney v. Eli Lilly & Co., 575 F. Supp. 228, 231 (D.S.D. 1983), aff’d, 739 F.2d 340 (8th Cir. 1984); Yarrow v. Sterling Drug, Inc., 263 F. Supp. 159, 162 (D.S.D. 1967), aff’d, 408 F.2d 978 (8th Cir. 1969).
Vermont:  Leavitt v. Ethicon, Inc., 524 F. Supp.3d 360, 368-70 (D. Vt. 2021).  Note:  A Vermont state trial court has also followed the rule. Estate of Baker v. University of Vermont, 2005 WL 6280644 (Vt. Super. May 5, 2005).
Wisconsin:  In re Zimmer Nexgen Knee Implant Products Liability Litigation, 884 F.3d 746, 751-52 (7th Cir. 2018); Karnes v. C. R. Bard, Inc.,  2019 WL 1639807, at *6-7 (W.D. Wis. April 16, 2019); Menges v. Depuy Motech, Inc., 61 F. Supp.2d 817, 830 (N.D. Ind. 1999); Monson v. AcroMed Corp., 1999 WL 1133273, at *20 (E.D. Wis. May 12, 1999); Lukaszewicz v. Ortho Pharmaceutical Corp., 510 F. Supp. 961, 963 (D. Wis. 1981), modified on other grounds, 523 F. Supp. 206 (D. Wis. 1981).  A Wisconsin state trial court has also followed the rule.  Straub v. Berg, 2003 WL 26468454, at *6 (Wis. Cir. Jan. 6, 2003).  A Pennsylvania appellate court has applied the rule under Wisconsin law:  Stange v. Janssen Pharmaceuticals Inc., 179 A.3d 45, 60 (Pa. Super. 2018).
Jurisdictions that Have Rejected the Rule in Prescription Medical Product Cases (0):
Effective 5/17/2016 State ex rel. Johnson & Johnson Corp. v. Karl, 647 S.E.2d 899 (W. Va. 2007), has been legislatively overruled.  Even before the legislature acted, however, the Karl holding has been limited in West Virginia to drugs subject to prescription drugs subject to direct-to-consumer advertising, with the learned intermediary rule still applying in medical device cases where no such advertising took place.   O’Bryan v. Synthes, Inc., 2015 WL 1220973, at *6-7 (S.D.W. Va. March 17, 2015); Wise v. C.R. Bard, Inc., 2015 WL 502010, at *4 (S.D.W. Va. Feb. 5, 2015); Tyree v. Boston Scientific Corp., 56 F. Supp.3d 826, 832-33 (S.D.W. Va. 2014).
Some of these categories – particularly “not in prescription medical product cases” – overlap with the other categories. Taking out the overlap, we believe that the current tally shows: (1) thirty-six jurisdictions (35 states and D.C.) in which either the legislature or the highest court (in more than seventy-five published high court opinions) has approved the learned intermediary rule in some context – notably Indiana is the most populous state not in this category; (2) an additional five states in which intermediate state appellate courts have adopted the learned intermediary rule; and (3) an additional nine jurisdictions (8 states and Puerto Rico) in which federal courts have made an Erie prediction that the state would adopt the learned intermediary rule. All told by our review, that’s all 50 states and two other jurisdictions that have precedent supportive of the learned intermediary rule.