Getting Started
What should I know before trying cannabis after 65?
Research summary prepared with AI assistance · Not authored by Ken Feldman or Nadine Laham · For general information only
~8 minute read
The short answer
If you're considering cannabis for the first time after 65 — or returning to it after decades away — the most important thing to know is that your body now processes cannabis differently than it did at 30. "Start low, go slow" is real advice, not a slogan. So is "talk to your doctor first." The cannabis available today is also dramatically more potent than what existed in 1975, and that gap matters for first-time older users.
What aging changes about cannabis effects
Several physiological changes that come with age affect how cannabis works in your body:
Slower metabolism
The liver enzymes that break down cannabis (mostly CYP3A4 and CYP2C9) become less efficient with age. The same dose that produces a 4-hour effect at 35 may produce a 6-7 hour effect at 70. This is more noticeable with edibles than inhaled products.
Higher body fat percentage, less lean mass
THC is fat-soluble. As body composition shifts with age, more of an active dose ends up stored in fat tissue and released gradually over the following hours and days. The result: a longer tail of subtle effects after the main experience has passed.
More medications on board
Polypharmacy is the medical term for being on multiple medications, and it becomes the norm after 65. Each medication is a potential interaction. Cannabis interacts with more medications than most people realize — see related questions on blood pressure medications and blood thinners specifically.
Greater sensitivity to cognitive effects
The same dose of THC that produced a manageable buzz at 30 can produce significant disorientation at 75. This is not a moral failing — it’s pharmacology. Older brains are more sensitive to the cognitive effects of THC, and the duration is longer.
Today's cannabis is not your college cannabis
If your last cannabis experience was in the 1960s, 70s, or 80s, the products available now are categorically different:
- Average THC potency in flower has roughly tripled since the 1990s, and current “premium” flower routinely tests at 25-35% THC.
- Concentrates and extracts (dabs, oils, vape cartridges) can reach 70-90% THC.
- Edibles are precisely dosed but the effect onset (60-90 minutes) makes overconsumption common — particularly for someone expecting the faster onset they remember from smoking.
A 1975 joint contained perhaps 5-10mg of THC and was usually shared among several people. A 2025 edible “single serving” gummy contains 5-10mg, intended for one person, and a single 100mg package contains what would have been a year’s worth of cannabis in 1975. The products look small, but the doses are not.
Worth knowing: If you're returning to cannabis after years away, treat yourself like a complete first-time user. Your prior experience does not predict how you'll respond now. Many older adults' first reintroduction to cannabis goes badly because they assumed it would feel like 1973 — and it doesn't.
What "start low, go slow" actually means
For an adult over 65 who is new to cannabis or returning after a long break, conservative starting points look like this:
For edibles
- Starting dose: 1-2.5mg THC. Many products are not made in this size. You may need to cut a 5mg gummy in half — or quarters.
- Wait at least 2 hours before considering more. Edibles have notoriously delayed onset.
- Try in the evening, at home, with no obligations the next morning.
For inhaled cannabis (vaporizer or smoking)
- One small inhalation, then wait 15 minutes. Onset is fast — you’ll know what you’re working with quickly.
- Avoid concentrates entirely as a first product. The dose is too unpredictable.
- Be aware that smoking has its own respiratory considerations independent of the cannabis effects.
For CBD-dominant products
CBD-only products have a different risk profile — much less risk of intoxication, but real risk of medication interactions (see the article on blood thinners). “Won’t get you high” is not the same as “has no effect on your body.”
The conversation worth having first
Before any of the above, if you have a primary care doctor you trust, the conversation is worth having. Many doctors are now more open to cannabis discussions than they were ten years ago, particularly for symptoms like chronic pain or sleep issues that have responded poorly to other treatments. Some are still uncomfortable with the topic. Either way, knowing where your doctor stands — and getting their read on your specific medication and condition picture — is more useful than guessing.
If your doctor is not the right person for this conversation, a pharmacist (particularly one trained in cannabis or geriatrics) can be an excellent alternative. They have detailed medication interaction knowledge and tend to be approachable.
What the evidence says
The age-related pharmacokinetic changes described above are well-established in geriatric pharmacology — this is Medically Documented material, even though most of it predates the cannabis-specific research. The clinical implications for cannabis use specifically have a smaller direct evidence base, but the underlying mechanisms are not in dispute.
Discuss with your doctor
- Your current full medication list (prescriptions, OTC, supplements) and any potential interactions
- Whether any of your conditions (cardiovascular, cognitive, balance) change the calculation
- What problem you're hoping cannabis might address, and whether other approaches have been fully tried
- Whether your state's medical cannabis program is appropriate for your situation
- What signs or symptoms should prompt you to stop and call them