# Does marijuana lose potency the longer it sits after being harvested? **URL:** \ **Category:** Factual Questions\ **Created:** [May 11, 2012, 2:06am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580 "2012-05-11T02:06:00Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![dnooman](https://avatars.discourse-cdn.com/v4/letter/d/839c29/32.png) [@dnooman](https://boards.straightdope.com/u/dnooman)\ **Post date:** [May 11, 2012, 2:06am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/1 "2012-05-11T02:06:00Z")
A friend of mine had a bag of some apparently high-potency weed that you could smell from a mile away while still sealed in a bag. He had the remnant of the bag several weeks later and it was practically odorless compared to before. He said he thinks it’s less potent now, but can’t be sure due to fluctuations in usage, his tolerance, etc. I wouldn’t think that THC evaporates, but the reduction in odor after a few weeks, and people’s tendency to label the really pungent stuff as “good”, makes me wonder if older weed has less kick. ---
**Author:** ![Interconnected\_Series\_of\_Tubes](https://avatars.discourse-cdn.com/v4/letter/i/13edae/32.png) [@Interconnected\_Series\_of\_Tubes](https://boards.straightdope.com/u/Interconnected_Series_of_Tubes)\ **Post date:** [May 11, 2012, 2:12am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/2 "2012-05-11T02:12:05Z")
In my nonscientific experience, not having subjected most of my chronic to a GC/MS: Pungency is often related to the moisture content of the herb than anything else - there seem to be some fairly volatile compounds that evaporate off an unsealed bag of weed pretty quickly - on a scale of weeks, I’d be skeptical that you’d really notice a difference. Super-dank odorous stuff is usually just _wet_, in my experience. I can, however, verify that marijuana left for several years will indeed oxidize a deep red/brown and become almost entirely unenjoyable. ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [May 11, 2012, 2:13am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/3 "2012-05-11T02:13:48Z")
You do realize that a simple experiment will yield more reliable results without resorting to the internet? ---
**Author:** ![dnooman](https://avatars.discourse-cdn.com/v4/letter/d/839c29/32.png) [@dnooman](https://boards.straightdope.com/u/dnooman)\ **Post date:** [May 11, 2012, 3:38am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/4 "2012-05-11T03:38:55Z")
> [@chacoguy](#): > > You do realize that a simple experiment will yield more reliable results without resorting to the internet? What sort of reliable and objective results are you advocating? “Resorting to the internet”? Please enlighten us all on how to do things in the proper manner. ---
**Author:** ![Yorikke](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yorikke/32/4335_2.png) [@Yorikke](https://boards.straightdope.com/u/Yorikke)\ **Post date:** [May 11, 2012, 5:03am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/5 "2012-05-11T05:03:07Z")
> [@dnooman](#): > > What sort of reliable and objective results are you advocating? > > “Resorting to the internet”? Please enlighten us all on how to do things in the proper manner. Dude, mellow out. Joe ---
**Author:** ![Esox\_Lucius](https://avatars.discourse-cdn.com/v4/letter/e/848f3c/32.png) [@Esox\_Lucius](https://boards.straightdope.com/u/Esox_Lucius)\ **Post date:** [May 11, 2012, 8:06am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/6 "2012-05-11T08:06:28Z")
I read once (in High Times, I think, but can’t be sure) that pot begins to lose potency noticeably after a year, and by two years is practically useless. When I smoked, I never had it long enough to test it, though. ---
**Author:** ![Hairy\_Bob](https://avatars.discourse-cdn.com/v4/letter/h/ecc23a/32.png) [@Hairy\_Bob](https://boards.straightdope.com/u/Hairy_Bob)\ **Post date:** [May 13, 2012, 8:52am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/7 "2012-05-13T08:52:39Z")
I know a guy who keeps a ‘special reserve’ of nice buds that he’s come across, some of them (he claims) have been in there over 3 years. On special occasions he’ll pull out a bud, pore over it for a while, take a big sniff and proclaim “Fine piece of Kali Mist there. 2009 vintage, if I’m not mistaken”, before crumbling it into a joint to share round. Never gets any complaints! Apparently it keeps best if it’s in an airtight container, packed full so there is as little air as possible in there, and it must be completely bone dry before sealing, or else it will sweat and go mouldy. He claims not to have seen a noticeable drop in potency (but after 3 years, how can you be sure, it’s pretty subjective after all) although it loses some of it’s flavour after a year or so, but there is always a pungent smell when the jar gets cracked open. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [May 13, 2012, 10:21am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/8 "2012-05-13T10:21:28Z")
Apparently it loses 4 to 20% of its THC per year depending on the heat according to [Marijuana Chemistry](http://books.google.com.au/books?id=1YeyucgLHnQC&pg=PA13&dq=marijuana+loss+of+potency+storage&hl=en&sa=X&ei=tYmvT5HBDO7JmAWc6PTFCQ&redir_esc=y#v=onepage&q=marijuana%20loss%20of%20potency%20storage&f=false). Not too bad really. ---
**Author:** ![bardos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bardos/32/1069_2.png) [@bardos](https://boards.straightdope.com/u/bardos)\ **Post date:** [May 13, 2012, 11:37am UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/9 "2012-05-13T11:37:06Z")
Yes, (cite: my personal experience.) ---
**Author:** ![Bozuit](https://avatars.discourse-cdn.com/v4/letter/b/edb3f5/32.png) [@Bozuit](https://boards.straightdope.com/u/Bozuit)\ **Post date:** [May 13, 2012, 4:25pm UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/10 "2012-05-13T16:25:10Z")
> [@dnooman](#): > > A friend of mine :dubious: ---
**Author:** ![Yorikke](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yorikke/32/4335_2.png) [@Yorikke](https://boards.straightdope.com/u/Yorikke)\ **Post date:** [May 13, 2012, 4:54pm UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/11 "2012-05-13T16:54:44Z")
> [@Hairy\_Bob](#): > > I know a guy who keeps a ‘special reserve’ of nice buds that he’s come across, some of them (he claims) have been in there over 3 years. On special occasions he’ll pull out a bud, pore over it for a while, take a big sniff and proclaim “Fine piece of Kali Mist there. 2009 vintage, if I’m not mistaken”, before crumbling it into a joint to share round. Never gets any complaints! Dude needs a cock-punching. Joe ---
**Author:** ![sniffo](https://avatars.discourse-cdn.com/v4/letter/s/e56c9b/32.png) [@sniffo](https://boards.straightdope.com/u/sniffo)\ **Post date:** [May 13, 2012, 9:53pm UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/12 "2012-05-13T21:53:35Z")
Stays potent for years if kept in airtight box in freezer. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [May 13, 2012, 9:58pm UTC](https://boards.straightdope.com/t/does-marijuana-lose-potency-the-longer-it-sits-after-being-harvested/621580/13 "2012-05-13T21:58:33Z")
> [@don\_t\_ask](#): > > Apparently it loses 4 to 20% of its THC per year depending on the heat according to [Marijuana Chemistry](http://books.google.com.au/books?id=1YeyucgLHnQC&pg=PA13&dq=marijuana+loss+of+potency+storage&hl=en&sa=X&ei=tYmvT5HBDO7JmAWc6PTFCQ&redir_esc=y#v=onepage&q=marijuana%20loss%20of%20potency%20storage&f=false). Not too bad really. 4-20% huh?