What Is the Potency and Stability of US Government Marijuana?



A tin of medical marijuana cigarettes, grown at the University of Mississippi, packaged by RTI. ProCon.org photos by Jeff Yablan.
In March 2005, ProCon.org obtained -- through a Freedom of Information Act (FOIA) request filed Feb. 9, 2004 of the National Institute on Drug Abuse (NIDA) -- a report that indicates that marijuana, in frozen storage, can retain its potency for at least 60 months (five years).

The 50-page report contained some of the following information:
I. Analysis of High Potency Marijuana Cigarettes (page 7 of PDF)
"Cigarette samples in this stability study were stored under three different temperature conditions (room, refrigerator, and frozen)... The average Delta-9-THC content... was 6.34 ± 0.21%. The average weight per cigarette was 0.734 ± 0.05g and the average moisture content was determined to be 11.32%."
II. Long-Term Stability Studies of Marijuana Cigarettes (page 8 of PDF)
"Six batches of cigarettes have been analyzed for the stability study so far. All batches of cigarettes have been stored under three temperature conditions. The study temperatures were frozen (-18 oC), refrigerated (4 oC), and room temperature (18 oC). All samples were stored in the dark.

All batches of cigarettes stored under these three temperature conditions have been analyzed quarterly for up to 52 months for Cigarette Batch No. 9223-0199-47 and 49 months for batches 9497-0499-99 and 9497-0499-103. Cigarette Batch No. 10074-0301-97 has been analyzed for 27 months so far. Batch No. 10604-0203-95 has been analyzed for 4 months and Batch No. 10747-1003-180A for time zero. The six study batches include a low potency batch, three medium potency batches, one high potency batch and one hand-rolled high potency batch.

Cannabinoid content was determined as a measure of cigarette stability...

The results to date show no observable decrease in Delta-9-THC content when cigarettes are stored at -18 oC.... Based on these stability studies, it appears that Delta-9-THC content remained relatively constant with no significant decomposition when the cigarettes were stored in a freezer. The expected slow decomposition is observed when stored at refrigerated or room temperature." [emphasis added]
III. Marijuana Cigarette Production (pages 17-41 of PDF)(all statistics refer to averages per cigarette produced by RTI and grown by the University of Mississippi)

  Type/Blend Weight Size Moisture Delta-9-THC Content
1. Mississippi-grown Jamaican, Special Hybrid and Mexican 0.779 ± 0.05 gram 85 mm x 25 mm 10.80 ± 0.27% 1.70% ± 0.15%
2. Mississippi-grown Mexican 0.689 ± 0.04 gram 85 mm x 25 mm 9.63 ± 0.69% 1.78% ± 0.04%
3. Mississippi-grown Mexican and Special Hybrid 0.734 ± 0.03 gram 85 mm x 25 mm 11.41 ± 0.95% 3.27% ± 0.24%
4. Mississippi-grown Jamaican, Special Hybrid and Mexican 0.733 ± 0.05 gram 85 mm x 25 mm 12.54 ± 0.49% 3.04% ± 0.21%
5. Placebo marijuana prepared by ethanol extraction of Mississippi-grown Mexican marijuana 0.702 ± 0.40 gram 85 mm x 25 mm 12.43 ± 0.45% 0.002% ± 0.00%
6. Hand-rolled placebo marijuana prepared by ethanol extraction of Mississippi-grown Mexican marijuana 0.760 ± 0.11 gram 70 mm x 25 mm 12.33 ± 0.83% 0.004% ± 0.00%
7. Mississippi-grown marijuana 0.790 ± 0.04 gram 85 mm x 25 mm 11.29 ± 0.26% 3.30% ± 0.41%
8. Mississippi-grown marijuana 0.813 ± 0.04 gram 85 mm x 25 mm 11.10 ± 0.42% 2.53% ± 0.19%
9. Mississippi-grown marijuana 0.790 ± 0.049 gram 85 mm x 25 mm 9.79 ± 0.24% 2.76% ± 0.18%
10. Mississippi-grown marijuana, Lot #1104-0107-01, Batch #984 0.7875 ± 0.02 gram 70 mm x 25 mm 11.22 ± 0.17% 6.44% ± 0.55%
11. Mississippi-grown marijuana, Batch #1182/1186 0.791 ± 0.16 gram 70 mm x 25 mm 11.46 ± 0.67% 7.18% ± 0.35%
12. Mississippi-grown marijuana 0.734 ± 0.05 gram 85 mm x 25 mm 11.32 ± 0.63% 6.03% ± 0.39%
13. Mississippi-grown marijuana, Batch #1182/1183/1195 0.743 ± 0.14 gram 70 mm x 25 mm 12.50 ± 0.12% 8.38% ± 0.41%
14. Mississippi-grown marijuana, Batch #1182/1186 0.791 ± 0.16 gram 70 mm x 25 mm 11.46 ± 0.67% 7.18% ± 0.35%


IV. Bulk Marijuana Production(pages 42-45 of PDF)
(all statistics refer to averages per batch of bulk marijuana produced)

  Type/Blend Moisture Delta-9-THC Content
1. Placebo marijuana prepared by ethanol extraction of Mississippi-grown Mexican marijuana 15.37 ± 0.10% 0.015% ± 0.01%
2. High potency marijuana plant material samples 9.63 ± 0.31% 6.84% ± 0.69%


See RTI report in PDF format