6. Dr. Petro did not offer a reasonable explanation to rule out stress, hormones, or endogenous vasoconstrictors as possible alternative causes of plaintiff's ICH
 940. Rule 706 expert Dr. Flockhart does not discuss why he believes Dr. Petro reliably ruled out stress, hormones, or endogenous vasoconstrictors as plausible causes of plaintiff's ICH. See generally Flockhart Report.
 941. The Court finds that Dr. Petro has not reliably ruled out these other plausible causes of plaintiff's ICH.
 W. Judicial Estoppel
 942. NPC is the manufacturer of Tavist-D, a drug which contains the active ingredient PPA. Plaintiff has also claimed that NPC manufactures Contac, the drug apparently ingested by the plaintiff prior to her ICH.
 943. The plaintiff asserts that because of its prior position in other cases, to-wit, Buggs v. Novartis and hundreds of PPA cases in the MDL Court in Seattle and in state courts throughout the country, that PPA cannot cause stroke, NPC should be judicially estopped from making any argument that Contac (PPA) or (sympathomimetic) played a role in plaintiff's stroke or that plaintiff's experts properly failed to rule out the role of Contac.
 944. Plaintiff argues that NPC should not obtain the benefit of the argument that PPA is a viable alternative cause of plaintiff's ICH. Otherwise, NPC is to be rewarded by its "playing fast and loose with the courts."
 945. Distilled to its essence, NPC's position is that the failure of the plaintiff's medical experts to properly rule out Contac or other amphetamine-type drugs in arriving at their differential diagnosis that Parlodel ® caused plaintiff's ICH renders their methodology or technique scientifically unreliable.
 946. Additionally, NPC's position is that it has not claimed that PPA as well as other possible causes of plaintiff's stroke have been proven by scientifically reliable evidence to cause stroke, but rather because of the low threshold plaintiff's experts applied in order to place Parlodel ® on the differential diagnosis requires that these alternatives be considered and reasonably ruled out if using sufficient diagnostic technology.
 947. The three medical experts appointed by the Court recognize the need for plaintiff's medical experts to rule out PPA or other amphetamine-type drugs in arriving at their differential diagnosis, and for the most part, even plaintiff's experts admit that PPA or other amphetamine-type drugs can cause stroke or in the least, can cause vasoconstriction or vasospasm.
 Conclusions of Law
 A. Conclusions of Law Regarding the Elements Required to Sustain a Pharmaceutical Products Liability Action Under Pennsylvania Law and Plaintiff's Burden of Proof Thereunder
 1. Proof of causation is a necessary element in a products liability action. Absent a causal relationship between the defendant's product and the plaintiff's injury the defendant cannot be held liable on a theory of negligence, strict product liability, or misrepresentation. O'Brien v. Sofamar, S.N.C., 1999 WL 239414 (E.D.Pa. 1999); see also Mellon v. Barre-National Drug Co., 431 Pa.Super. 175, 636 A.2d 187, 191 (Pa.Super. 1993), appeal denied, 538 Pa. 658, 648 A.2d 789 (1994).
 2. As plaintiff's experts acknowledge, to meet her causation burden, plaintiff must first establish that Parlodel ® is capable of cautsing ICH (general causation). She must then establish that, in her particular case, Parlodel ® did in fact cause her ICH (specific causation). See Heller v. Shaw Indus., 1997 WL 535163 at *6 (E.D.Pa. 1997), aff'd, 167 F.3d 146 (3d Cir. 1999); DeLuca v. Merrell Dow Pharm., Inc., 911 F.2d 941, 958 (3d Cir. 1990); In re Consol. Parlodel ® Litig., 182 F.R.D. 441, 445 n. 3 (D.N.J. 1998). If plaintiff has not demonstrated sufficiently reliable evidence of general causation, her claims fail and there is no need to consider specific causation. Wade-Greaux v. Whitehall Labs., 874 F. Supp. 1441, 1485 (D.Vi.), aff'd without op., 46 F.3d 1120 (3d Cir. 1994) ("[t]o prove specific causation, plaintiff must first prove that the products at issue can cause [injury] and must then exclude other possible causes for the plaintiff's injury") (emphasis in original); see also Merrell Dow Pharm., Inc. v. Havner, 953 S.W.2d 706 (Tex. 1997) (opinion based on "differential diagnosis" is excluded where there is no scientific basis for general causation). Plaintiff must prove medical causation to a "reasonable degree of medical certainty." Wilson v. Wigen, 1998 WL 199649, at *4 (E.D.Pa. 1998) (setting out standard in medical malpractice action); Watkins v. Hospital of the University of Pa., 1999 Pa.Super. 181, 737 A.2d 263 (1999) (same).
 3. Far from constituting some type of dubious "shield," as plaintiff contends, the requirement of general causation as an aspect of a scientifically-reliable causation opinion is the very essence of Daubert. See General Elec. Co. v. Joiner, 522 U.S. 136, 146, 118 S.Ct. 512, 139 L.Ed.2d 508 (1997) (tenuous temporal link and lack of studies linking product to disease impermissibly left only the "ipse dixit of the expert" to support his conclusion). Without admissible evidence that Parlodel ® is capable of causing postpartum stroke in the first place, plaintiff's experts cannot reliably perform the differential diagnoses that they contend they have employed.
 4. There are a number of cases in which summary judgment has been granted to NPC on comparable Parlodel ® claims. See Brumbaugh v. Sandoz Pharm. Corp., 77 F. Supp.2d 1153, 1999 WL 1104539 (D.Mont. 1999) (Att. 39); Revels v. Sandoz Pharm. Corp., No. 95-11076, Orders of Mar. 13 and Apr. 1, 1998 (201st Jud. Dist., Travis County, Tex.) (excluding general causation evidence in similar Parlodel ® case as "not sufficiently scientifically reliable or relevant" and granting summary judgment) (Att. 40), aff'd, 1999 WL 644732 (Tex.App. — Austin Aug. 26, 1999) (Aboussie, C.J.), petition for review denied.
 5. This Court agrees with Brumbaugh: "The issue of specific causation is material, however, only if plaintiff can demonstrate general causation between Parlodel ® and her injury." Brumbaugh, 77 F. Supp.2d at 1155 n. 1; see also Revels, at *5 ("we must hold that in the absence of a scientifically reliable basis for a conclusion regarding general causation, the trial court did not abuse its discretion by excluding expert testimony that Parlodel ® was the specific cause of Mrs. Revel's death.").
 6. In a case such as this one involving complex issues of causation not readily apparent to the finder of fact, plaintiff must present admissible expert testimony to carry her burden. See Heller v. Shaw Indus., Inc., 167 F.3d 146, 153 (3d Cir. 1999) (expert testimony required to establish that alleged respiratory ailments were caused by carpet fumes). If her expert testimony cannot support both general and specific causation, summary judgment for the defendant must be granted.
 7. Such opinions must be expressed to a reasonable degree of medical certainty. Heller, 167 F.3d at 153 n. 4; In re: Paoli, 2000 WL 1279922 at *2 (E.D.Pa. 2000). Opinions merely expressing "possibilities" do not suffice to support the admissibility of expert testimony. See Saldana v. Kmart Corp., 260 F.3d 228, 234 (3d Cir. 2001) ("the mere possibility that something occurred in a particular way is not enough, as a matter of law, for a jury to find it probably happened that way"); Booth v. Black & Decker, Inc., 166 F. Supp.2d 215, 222-23 (E.D. Pa. 2001) (metaphysical possibility of causation insufficient to establish product liability claim); In re: Paoli, 2000 WL 1279922 at *5 ("possible" link between vaccine and illness "not enough to support expert testimony") (citing Mazur v. Merck & Co., 742 F. Supp. 239, 265 (E.D.Pa. 1990)); In re: Paoli R.R. Yard PCB Litig., 2000 WL 274262 at *6 (E.D.Pa. 2000) ("possible" diagnosis too speculative to satisfy Rule 702).
 8. Plaintiff bears the burden of demonstrating that each of her proffered experts is qualified to render an expert opinion, that the opinion is reliable, and that the opinion would assist the trier of fact in resolving a disputed issue of material fact — here, causation. Fed.R.Evid. 702; see, e.g., Danbert v. Merrell Dow Pharm., 43 F.3d 1311, 1316 (9th Cir.), cert. denied, 516 U.S. 869, 116 S.Ct. 189, 133 L.Ed.2d 126 (1995) (Daubert II).
 9. In challenging plaintiff's proposed expert testimony, defendant is not required to come forward with "scientific evidence" negating plaintiff's claims. Rather, defendant is entitled to point out deficiencies in plaintiff's proof. E.g., Celotex Corp. v. Catrett, 477 U.S. 317, 325, 106 S.Ct. 2548, 91 L.Ed.2d 265 (1986) ("the burden on the moving party may be discharged by `showing' — that is pointing out to the district court — that there is an absence of evidence to support the nonmoving party's case").
 10. When a claimant produces insufficient competent evidence in support of an element she would be required to prove at trial, summary judgment is required. See Celotex, 477 U.S. at 322-23, 106 S.Ct. 2548 ("Rule 56(c) mandates the entry of summary judgment . . . against a party who fails to make a showing sufficient to establish the existence of an element essential to that party's case, and on which that party will bear the burden of proof at trial"); Estate of Zimmerman v. Southeastern Penn. Transp. Auth., 168 F.3d 680, 684 (3d Cir. 1999) (failure of plaintiffs in personal injury case to establish triable issue of fact on any element on which they would bear burden of proof at trial, including causation, is grounds for summary judgment).
 B. Standards Regarding the Review of Proposed Expert Testimony Under Fed.R.Evid. 702, Daubert, Kumho Tire, and Court of Appeals for the Third Circuit Jurisprudence
 11. Federal Rule of Evidence 702 states:
If scientific, technical, or other specialized
knowledge will assist the trier of fact to understand
the evidence or to determine a fact in issue, a
witness qualified as an expert by knowledge, skill,
experience, training, or education, may testify
thereto in the form of an opinion or otherwise, if
(1) the testimony is based upon sufficient facts or
data, (2) the testimony is the product of reliable
principles and methods, and (3) the witness has
applied the principles and methods reliably to the
facts of the case.