Therapeutic Cannabis
What factors will influence my decision to try therapeutic cannabis?
Research summary prepared with AI assistance · Not authored by Ken Feldman or Nadine Laham · For general information only
~8 minute read
The short answer
The honest answer is it depends — and what it depends on is you. Trying therapeutic cannabis is not a single yes-or-no choice. It is a set of smaller questions about your body, your health history, the medicines you already take, and how you live from day to day. The very same product can ease one person’s symptoms and cause real trouble for another. The factors below are the ones that matter most. None of them settles the question alone, but together they paint a picture you and your doctor can actually use. The goal here is not to talk you into cannabis or out of it, but to help you ask sharper questions.
Your age, weight, and sex
Older bodies handle cannabis differently. As we age, we tend to carry more body fat and less water, and the liver and kidneys clear substances more slowly. THC, the part of cannabis that causes a high, is fat-soluble, so it can linger longer and feel stronger in an older adult than the same dose would in a younger one. Body weight matters too: a dose that feels mild for a larger person can feel intense for a smaller one. Biological sex appears to play a part as well, with some research suggesting women may be more sensitive to certain effects, partly because of differences in body composition and hormones. The practical lesson is the same across the board — start low and go slow.
Your liver, lungs, and mental health
Three systems deserve a close look. The liver breaks down both THC and CBD, so reduced liver function can let these compounds build up in the body. The lungs matter because smoking or vaping cannabis irritates the airways and can worsen conditions like COPD (chronic obstructive pulmonary disease) or asthma — for many older adults, edibles, tinctures, or capsules are gentler choices. Your psychiatric and psychological history is just as important. Higher-THC products can trigger or worsen anxiety, and in rare cases cause confusion or paranoia. Anyone with a personal or family history of psychosis or bipolar disorder should be especially cautious and involve a doctor early.
Other conditions you already live with
Most older adults are managing more than one health issue at a time, and those conditions shape the decision. This is the question of co-morbidity — the other illnesses that live alongside the one you hope to treat. Heart disease is a clear example: THC can briefly raise heart rate and shift blood pressure, which matters a great deal if you have a cardiac condition. A history of falls, frailty, or balance problems also raises the stakes, since cannabis can cause dizziness or drowsiness. The point is not that any single condition rules cannabis out. It is that the full picture, rather than one symptom in isolation, should guide the choice. Diabetes, kidney trouble, and digestive conditions all belong in that picture too.
The medicines you already take
This is one of the most important factors, and the easiest to overlook. CBD and THC are both processed by the same family of liver enzymes (the CYP450 system) that handle many common prescriptions. CBD in particular can slow the breakdown of certain drugs, raising their levels in your blood — a bit like the way grapefruit interacts with some medications. The more prescriptions you take, the greater the chance that one of them overlaps with cannabis, and older adults often take several at once. THC carries its own concerns, since it can add to the drowsiness of sleep aids, sedatives, and some pain medicines.
Worth knowing: Blood thinners such as warfarin are the classic example. CBD can raise warfarin levels and increase the risk of bleeding, so anyone taking it needs closer monitoring. Sedatives, some seizure medicines, and certain heart and blood-pressure drugs can interact as well. Bring your full medication list — including over-the-counter products and supplements — to the conversation.
Experience, method, and lifestyle
Your history with cannabis shapes what to expect. Someone who tried it decades ago is often surprised: today’s products are far stronger than the cannabis of the 1970s, so a returning user should treat it as a brand-new medicine. How you take it matters too. Inhaled cannabis works within minutes but fades quickly, while edibles can take one to two hours to take hold and last much longer — which makes it easy to accidentally take too much. Your daily life counts as well. Whether you drive, live alone, drink alcohol, or have someone nearby to help all affect how safely you can experiment. Alcohol in particular can multiply cannabis’s effects, so combining the two deserves real caution.
Allergies and everyday safety
Two practical checks round out the list. Cannabis allergies are uncommon but real; people can react to the plant itself or to additives in a product, with symptoms ranging from a rash to trouble breathing, so mention any plant or pollen allergies to your provider. Safety is the final piece. Because cannabis can cause drowsiness and unsteadiness, it raises the risk of falls and head injury — a serious concern for older adults, and especially for anyone on blood thinners, where a fall can mean a dangerous bleed. Dry mouth is also common and, over time, can harm teeth and gums, so dental health is worth keeping in view.
What the evidence says
It helps to be honest about how strong the science is behind each factor. Medically Documented: the role of the liver’s CYP450 enzymes in cannabis drug interactions is well established, as is the short-term rise in heart rate that THC can cause. Promising: the influence of age, body composition, and sex on how cannabis is felt is supported by a growing body of research, though it is still being mapped. Anecdotal: much of what we believe about the “right” method or dose for a given person still comes from self-report and clinical experience rather than large trials. Knowing which tier you are standing on keeps expectations realistic.
Practical things to think about
- Make a full list — write down every medication, supplement, and health condition before you decide anything.
- Start low, go slow — begin with the smallest reasonable dose and wait before taking more, especially with edibles.
- Pick the gentlest method — for most older adults, tinctures or capsules avoid the lung risks that come with smoking.
- Set up your space — clear away fall hazards and keep water within reach for the dry mouth that often follows.
- Let someone know — tell a trusted person the first few times you try it, particularly if you live alone.
- Track how you feel — keep a simple note of dose, timing, and effects to share at your next appointment.
Discuss with your doctor
- Whether any of your current medications could interact with THC or CBD.
- How your liver, kidney, heart, or lung conditions might change the picture.
- The safest method and the lowest sensible starting dose for your situation.
- The warning signs that mean you should stop and call for help.