Table 3 shows that heroin is approximately 3 to 4 times stronger than morphine, so 3 mg of heroin is equal to about 10 mg of morphine. It should be noted that generally the data is very supportive of this equivalence between certain doses of morphine and heroin, an equivalence which is three-fold, including pharmacological effect, blood morphine levels, and most importantly, toxicological effect. To the extent that differences have been established, there is no doubt that a large intravenous heroin overdose is even deadlier and faster acting than an "equivalent" large intravenous morphine overdose.

Table 4, below, shows the generally accepted dose and blood level equivalents of intravenous heroin. More than 100mg of morphine (30 mg heroin) almost always presents major complications. Doses over 250mg morphine (75 mg - 80 mg heroin) are usually associated with certain death, i.e. 75 mg - 80 mg of heroin, leads to a blood level of approximately 0.5mg per liter, the high end of toxic doses. Thus it is clear that Cobain ingested at least triple the lethal dose for even the most severe addict. This is basically a linear conversion, which is not true for all drugs, but is shown to be true for intravenous morphine and heroin overdoses in addicts, as shown in the several of the studies referenced. If he were not a severe addict, then 1.52 mg per liter potentially represents up to 75 times the lethal dose. Details regarding common heroin doses are explained by Tong & Pond who state that "the basic unit of sale is the 'tenth,' which is 1/10 of a gram or 100 mg of pure drug. This unit...provides approximately 4 'hits' or doses. A quarter of a tenth (25 mg powder) contains 20 mg to 24 mg of heroin, which is more than the usual street addict is used to per dose." (94). Severe addicts may require 3 such hits in 1 dose, 4 times daily, while Cobain's blood morphine level represents a dose of approximately 8 to 10 such "hits." More importantly, it must be remembered that the actual size of the dose does not matter very much, rather it is the blood morphine level in particular, a what it tells us, which is the true forensic evidence, the incontrovertible fact. Although it is definitely possible to make a reasonable estimate at the obviously massive dose Cobain received based on data from other intravenous heroin overdoses in addicts, an exact dose figure cannot be determined without a full forensic report regarding the morphine levels in various other organs and tissues. Regardless of the specific dose of heroin, the 1.52mg/L blood morphine level in Cobain allows for the conclusion to be made that he was immediately incapacitated or dead based on the simple fact that no other instance exists on record indicating otherwise, even remotely.