New to medical cannabis? Start here.
Starting medical cannabis can feel like a lot at once: new words, new products, and a counter full of choices. This page covers the basics in plain words: how the forms differ, how to start low and go slow, how to read the amount on a label, and how to stay safe. It is general information, not medical advice. Your qualified physician knows your health and your medicines, and your certification says which forms you may get and how much.
Start low, go slow
Begin with a small amount, wait long enough to feel its full effect, and only then decide whether you need more. If you do, raise it a little at a time over several days. You can always take a little more later; you cannot take less once it is in your system.
The goal is the lowest dose that gives you the therapeutic response you are looking for, not the strongest product on the menu. Staying at that dose lowers the risk of the unwanted effects that too much THC can cause. A higher THC number is a measure of strength, not of quality, and not of how well a product will work for you.
Remember that everyone reacts differently to cannabis. With edibles in particular, potency varies widely, and a small increase in dose can cause a big change in effect. Food matters too: whether you have eaten in the last two hours, and what you ate, can change how the same edible dose affects you. A meal, especially a fatty one, generally delays the onset and increases how much THC your body absorbs, so the same edible can hit later and harder than it did on an empty stomach.
How each form differs
How you take cannabis changes how fast it starts and how long it lasts. The times below are typical ranges from Health Canada's consumer information. Everyone is different, and some lingering effects, such as tiredness, can last 12 to 24 hours.
| Form | Products | Starts | Lasts |
|---|---|---|---|
| Inhaled | Flower and pre-rolls, vapes, concentrates, metered dose inhalers | Seconds to minutes; the full effect in 10 to 30 minutes | About 2 to 4 hours |
| Swallowed | Edibles, capsules, and tinctures that are swallowed | 30 minutes to 2 hours; the full effect in up to 4 hours | About 4 to 8 hours |
| Under the tongue | Tinctures and sprays held under the tongue | Often sooner than swallowing | Varies: whatever is swallowed acts like an edible |
| On the skin | Lotions, balms, and topical patches | Most stay where they are applied and are not meant to cause a high | |
A transdermal patch is different from a topical one: it is made to carry cannabinoids through the skin into the bloodstream, so its effects can be felt throughout the body.
Edibles: give them time
The most common mistake with edibles is taking more because nothing seems to be happening yet. An edible can take up to 2 hours to begin working and up to 4 hours to reach its full effect, so wait at least 2 hours before deciding to take more; longer is safer. Swallowed THC passes through the liver first, which turns some of it into a stronger form. That is part of why an edible can feel stronger, and last longer, than inhaling the same amount.
Reading the amount on a label
- Edibles list the mg of THC (and CBD) in each piece and in the package: a 100 mg package of ten gummies is 10 mg a piece. In Florida, a single serving may contain no more than 10 mg of THC, and a multi-serving package no more than 200 mg of Total Active THC. A piece can be cut for a smaller amount.
- Tinctures and oils list the mg in the whole bottle, and usually in each mL. Divide to find what one dropper or one measured dose holds.
- Flower, vapes, and concentrates list Total THC as a percentage: a gram at 20% Total THC holds about 200 mg of THC. How much of it reaches you depends on how you inhale, so start with one small inhalation and wait for its full effect, 10 to 30 minutes, before taking another.
- CBD products come in three kinds on Florida menus: CBD-Forward, CBD:THC Ratio, and Low-THC Cannabis. The CBD filter on the Product Index finds all three.
The lab report for your batch shows what was measured in it: how to read one, including the serving math on an edible's.
Staying safe
- Do not drive or operate machinery after using cannabis. Its effects on attention and reaction time can last longer than you feel them.
- Keep it locked up, out of sight and reach of children and pets. Edibles can look like candy and can poison a child.
- Skip the alcohol when you use cannabis: together, their effects add up.
- Tell your physician and your pharmacist what you use. Cannabis can interact with other medicines, and some of those interactions can be serious.
- Older adults: start with an even smaller amount, and take care standing up. Cannabis can cause dizziness, and dizziness can lead to a fall.
- Where you use it: Florida law does not allow medical marijuana to be used on public transportation, in a public place, or in a vehicle, boat, or aircraft (low-THC cannabis that is not smoked is the exception in each of these), on the grounds of a school, or at your place of employment unless your employer allows it. Smoking is not allowed in an enclosed indoor workplace.
If you take too much
Too much THC can be frightening: a racing heart, anxiety, or feeling very unwell. It passes as the THC wears off. Go somewhere calm and safe, sit or lie down, sip water, and have someone stay with you if you can. Do not take more, and do not drive.
Call 911 for chest pain, trouble breathing, a seizure, or someone who will not wake up. For advice any time, call the free Poison Help line, 1-800-222-1222, and call it right away if a child has eaten cannabis. For a pet, call your veterinarian.
Before your first visit
- Bring your Medical Marijuana Use Registry identification card and a photo ID.
- Know which forms your certification allows, and how much. Your qualified physician sets them, and you can see them in the Medical Marijuana Use Registry.
- Look at the lab report for what you are considering: How to read a lab report.
- See what your daily amount will cost a month: What my medicine costs.
- Keep a simple record of what you took, how much, when, and how you felt. It helps you and your physician find what works. My list keeps a note on each product you save, in your own browser.
Places on the Product Index to look for smaller amounts: edibles, which are labeled by the mg in each piece, CBD products, and Low-THC Cannabis.
Where these figures come from: how fast each form starts and how long it lasts, from Health Canada's Consumer information: Cannabis; Florida's limits on edibles, from the Office of Medical Marijuana Use's edibles rule, as the Lab Report Guide sets out; where use is allowed, from s. 381.986(1)(k), Florida Statutes. This page is general information for adult patients and caregivers, not medical advice.