The only issue in this appeal is whether we will recognize a common-law defense of medical necessity in a marijuana manufacturing case. The district court denied the defense, and we affirm.
I. Facts and Prior Proceedings.
When Floyd County sheriffs deputies went to Lloyd Bonjour’s home to serve warrants on him, they observed marijuana plants and bagged marijuana. Bonjour was initially charged with multiple offenses, but by agreement with the State the charges were reduced to one: manufacture of marijuana in violation of Iowa Code section 124.401 (1999).
Prior to trial, Bonjour filed a notice of his intent to rely on a defense of medical necessity. The State resisted by filing a motion in limine, and Judge Stephen Carroll held an evidentiary hearing on it. At the hearing,'Bonjour testified that he is in his sixties and suffers from Acquired Immune Deficiency Syndrome (AIDS). His physician, Dr. Jeffery Meier, assistant professor in internal medicine at the University of Iowa, testified that because of the AIDS virus Bonjour must take a variety of toxic medications. This toxic combination causes side effects such as poor appetite, nausea, neuropathy, and diarrhea.
Dr. Meier originally treated these side effects by prescribing Marinol, which is a synthetic version of THC (the active substance in marijuana). Dr. Meier stated that Bonjour demonstrated some signs of improvement while on Marinol, but his symptoms were better controlled when he began using marijuana. Dr. Meier conceded that his only basis for this assessment was the information he received from Bonjour about what he had been taking. Nevertheless, Dr. Meier concluded that “one could say that marijuana might have been lifesaving in this particular case.” The effectiveness of marijuana in the treatment of AIDS is not an issue in this appeal.
*512Judge Carroll granted the State’s motion in limine and barred Bonjour from presenting his medical-necessity defense. The case proceeded to a bench trial before Judge Bryan McKinley, who found Bonj-our guilty. On appeal Bonjour’s sole issue is the denial of his medical-necessity defense'.
II. The Medical-Necessity Defense.
We have considered necessity defenses in other contexts. E.g., State v. Walton, 311 N.W.2d 113, 115 (Iowa 1981); State v. Ward, 170 Iowa 185, 188-89, 152 N.W. 501, 502 (1915). In Walton, which involved a defendant’s illegal carrying of a firearm for self-protection, we rejected the defense. In Ward, which involved a defendant shooting a deer to protect his crop, we allowed it. We have never decided a medical-necessity case.
We have said the rationale for the necessity defense in general lies in the “defendant being required to choose the lesser of two evils and thus avoiding a greater harm by bringing about a lesser harm.” Walton, 311 N.W.2d at 115. As one commentator has stated, “the law ought to promote the achievement of higher values at the expense of lesser values, and sometimes the greater good for society will be accomplished by violating the literal language of the criminal law.” 2 Wayne R. LaFave, Substantive Criminal Law § 10.1 (2d ed.2003) [hereinafter LaFave].
However,
[t]he defense of necessity is available only in situations wherein the legislature has not itself, in its criminal statute, made a determination of values. The mere fact that the statute under which defendant is charged has some exceptions from liability not covering the situation at hand does not inevitably mean there has been a legislative determination contrary to defendant’s position. But if the legislature has made a determination on this matter one way or another, then its decision governs.
Id. (footnotes omitted).
As the New Jersey Supreme Court noted:
The [necessity] defense is based on public policy. In.essence it reflects a determination that if, in defining the offense, the legislature had foreseen the circumstances faced by the defendant, it would have created an exception. It would have balanced the competing values and chosen the lesser evil. Obviously, then, the defense is available at common law only when the legislature has not foreseen the circumstances encountered by a defendant. If it has in fact anticipated the choice of evils and determined the balance to be struck between the competing values, defendants and courts alike are precluded from reassessing those values to determine whether certain conduct is justified.
State v. Tate, 102 N.J. 64, 505 A.2d 941, 946 (1986).
Similarly, we look to our substance-abuse statutes to determine whether the legislature has already struck a balance between the two harms presented (i.e., the harm of manufacturing marijuana versus the harm of denying AIDS victims the right to use it) or left the issue open. If it has left the issue open, there may be room for recognizing a common-law necessity defense. See id.; LaFave § 10.1.
Iowa Code chapter 124 restricts the use of controlled substances and divides them into five “schedules.” Marijuana is listed as a Schedule I controlled substance. Iowa Code § 124.204(4)(m). Iowa Code section 124.203 states that a Schedule I substance “[h]as a high potential for abuse” and “[h]as no accepted medical use in treatment in the United States” or *513“lacks accepted safety for use in treatment under medical supervision.”
Despite the legislature’s conclusion that marijuana has no allowable medicinal use, it left the door open for possible medical uses in the future. Under section 124.204(4)(m), marijuana is a Schedule I controlled substance “except as otherwise provided by rules of the board of pharmacy examiners for medicinal purposes.”
The legislature has recognized that marijuana may have medical value. This is apparent from Iowa Code section 124.206(7)(a), which provides marijuana may become a Schedule II substance (which is one that “has currently accepted medical use in treatment in the United States, or currently accepted medical use with severe restrictions,” Iowa Code § 124.205(2)). As to marijuana, the “severe restriction” is that its use must be for medicinal purposes “pursuant to rules of the board of pharmacy examiners.” Id. § 124.206(7)(a) (emphasis added). The defendant does not contend, and we do not believe, that the Board of Pharmacy Examiners has adopted any rules that would make marijuana use legal.
These statutes show that our legislature has foreseen the potential medical uses for marijuana but has deferred on the issue until the Board of Pharmacy Examiners has acted. The legislature has, therefore, made the kind of “determination of values” in this debate — enforcement of the marijuana ban versus its potential medical value — that effectively forecloses our recognition of a common-law necessity defense. See Tate, 505 A.2d at 946; LaFave § 10.1.
Part of the problem in recognizing a medical-necessity defense is defining the parameters to place on it. Medical-necessity defenses have been sought in connection with treatment of a wide variety of conditions. In addition to AIDS, these have included complications of diabetes (People v. Mower, 28 Cal.4th 457, 122 Cal.Rptr.2d 326, 49 P.3d 1067, 1071 (2002)); epilepsy (State v. Hanson, 468 N.W.2d 77, 77-78 (Minn.Ct.App.1991)); emotional anxiety caused by head injury (State v. Williams, 93 Wash.App. 340, 968 P.2d 26, 28 (1998)); effects of chemotherapy (Seeley v. State, 132 Wash.2d 776, 940 P.2d 604, 606-07 (1997)); spasticity due to quadriplegia (Tate, 505 A.2d at 942); glaucoma (State v. Bachman, 61 Haw. 71, 595 P.2d 287, 288 (Haw.1979)); rheumatoid arthritis (State v. Hastings, 118 Idaho 854, 801 P.2d 563, 564 (Idaho 1990)); and multiple sclerosis (State v. Poling, 207 W.Va.299, 531 S.E.2d 678, 680-81 (2000)). There are, no doubt, many other maladies for which marijuana treatment may be sought.
Although some states have adopted the defense of medical necessity by statute, Iowa has not. And most jurisdictions to consider the issue under common law have rejected it. See, e.g., United States v. Oakland Cannabis Buyers’ Coop., 532 U.S. 483, 491-93, 121 S.Ct. 1711, 1718-19, 149 L.Ed.2d 722, 732-34 (2001); State v. Cramer, 174 Ariz. 522, 851 P.2d 147, 149 (Ariz.Ct.App.1992); People v. Kratovil, 351 Ill.App.3d 1023, 286 Ill.Dec. 868, 815 N.E.2d 78, 90-92 (2004); Hanson, 468 N.W.2d at 78-79; Tate, 505 A.2d at 946; Williams, 968 P.2d at 30; Poling, 531 S.E.2d at 684-85. But see Jenks v. State, 582 So.2d 676, 679 (Fla.Dist.Ct.App.1991).
Our conclusion that the legislature did not leave the door open to a common-law necessity defense might draw into question our deer-shooting case, State v. Ward, previously mentioned. In that case, the legislature had considered the possibility of a need to shoot nuisance deer, in violation of the general statute, by providing a remedy:
When it shall become necessary in the opinion of the state game warden or his deputies to kill or capture any deer now *514running at large within this state, it shall be done under the authority and direction of the state fish and game warden. ...
Ward, 170 Iowa at 190, 152 N.W. at 502. In Ward the defendant did not enlist the aid of the state game warden but rather shot the deer himself. Id. at 187, 152 N.W. at 501. Despite the fact the legislature had weighed the possible need to dispose of nuisance deer and provided a means to do it other than by self-help, we allowed the defendant to assert a necessity defense. Id. at 189, 152 N.W. at 502.
While our disposition of the present case seems to be inconsistent with Ward, we believe the medical use of marijuana is qualitatively different from the legal issue in Ward. Use of marijuana is a public-policy issue best suited for the legislature because it is driven by legal, moral, philosophical, and medical concerns that are ill-suited for resolution by this court. This is especially true in view of the fact the legislature has deferred the initial decision on the matter to the Board of Pharmacy Examiners.
As the law stands now, manufacturing marijuana is prohibited and marijuana has no recognized medicinal value. The issue in this case is not whether the legislature has “acted to preclude the defense by a clear and deliberate choice,” Commw. v. Hutchins, 410 Mass. 726, 575 N.E.2d 741, 744 (1991). It has not. What it has done, however, is to clearly and deliberately decide what the procedure shall be for making that determination. That procedure is to defer to the Board of Pharmacy Examiners, which is far better equipped than this court — and the legislature, for that matter — to make critical decisions regarding the medical effectiveness of marijuana use and the conditions, if any, it may be used to treat. The board has not done so, and we, by legislative directive, must wait until it does.
While an appeal is made here for us to recognize this defense on humanitarian grounds, we may do so only under established principles of law. In other contexts, we have been asked to ameliorate harshness in legislative enactments and have declined. In Schultze v. Landmark Hotel Corp., 463 N.W.2d 47 (Iowa 1990), for example, the plaintiff asked us to engraft a discovery rule on the statute of limitations under Iowa Code section 614.1(9). We said the
plaintiff raises an equitable concern. He argues that the discovery rule should apply to section 614.1(9) because of the “extreme hardship” and “strained and impractical result” it works on survivors. A few courts have allowed equitable concerns and potential hardship to plaintiffs to influence their decision applying the discovery rule in the face of a statute expressly providing that an action must be commenced within a specified period of time after death. We find, however, this line of cases to be unsound authority because they are based on judicial discretion used to implement notions of fairness rather than giving effect to the priorities that the legislature has set forth in an express statutory provision.
Schultze, 463 N.W.2d at 51 (emphasis added) (citations omitted); accord Schlote v. Dawson, 676 N.W.2d 187, 193 (Iowa 2004).
In view of the legislature’s measured plan for studying this issue, it would be inappropriate now for us to leapfrog the legislature and the Board of Pharmacy Examiners by simply recognizing the medicinal value, and the legality, of marijuana use. Informed medical decisions need to be made regarding whether in fact marijuana has the claimed effects. An even more significant issue is how far such a defense should be extended. Resolution of *515these issues must await further study by the pharmacy board and the legislature.
We believe the trial court correctly denied the proffered medical-necessity defense, and we therefore affirm.
AFFIRMED.
All justices concur except TERNUS, J., who concurs in result only, and WIGGINS, J., and LAYORATO, C.J., who dissent.