Medical Marijuana 101: 10 Things You Should Know Before Using The Drug

As medical marijuana is introduced in Massachusetts, here are 10 things to know about using it.

Whether you are using marijuana for the first time, or trying it for a new ailment, those who praise its benefits say you should be prepared for a period of trial and error. Because:

1) What works for one patient may not work for you. The difference may be in the marijuana, but patients also respond to drugs differently based on age, race, gender, genetics and other factors. (The Food and Drug Administration takes many of these factors into account when testing legal drugs.)

2) All pot is not alike. Every strain of marijuana has a different balance of cannabinoids, the chemical compounds that are unique to marijuana, some of which have medicinal value. The two most common are THC, which can make people high, and CBD, which offsets the effects of THC and is believed to prevent muscle spasms and seizures.

3) Even within the same strain, the intensity of cannabinoids will vary. Take Blue Dream, one of the more popular strains these days. Blue Dream from one grower might have 5 percent THC, but if you change buyers, your next batch of Blue Dream might have 25 percent THC and produce a strong high.

(Here are some examples of the range of chemicals from the first marijuana testing lab to open in Massachusetts.)

4) Patients with a weak or compromised immune system should confirm that their marijuana is free of contaminants: heavy metals, mold, mildew and pesticides. Testing for these contaminants will be required of products sold by dispensaries in Massachusetts.

5) Once you find a strain that has the balance of THC, CBD or other cannabinoids that you want, you'll have to figure out how much to take. Dispensaries will set doses in Massachusetts. These recommendations may or may not be based on scientific research, because the research is limited.

6) There are many ways to ingest marijuana. You can smoke it, use a vaporizer, eat it in prepared foods, or your own cookies or sauces, or in a concentrated liquid form, or drinks. In this state, dispensaries will be required to make all the marijuana-infused products that they sell. Products sold outside a dispensary may not have been tested and may not be considered legal.

7) How often you take or use marijuana may depend on how you ingest the drug. The effects of smoking or vaporizing are immediate but don't last as long as eating cookies, where digestion slows but prolongs the effects. If you've had a few bites of a cookie baked with marijuana and you don't feel anything, wait at least one hour before eating more to avoid taking too much.

8) How you store your marijuana may affect the potency. Some patients say heat degrades the potency of tinctures and food products, so they recommend refrigeration.

The state will require expiration dates, but the science used to set these dates may vary from one dispensary to the next.

9) THC in particular may produce side effects, and some heavy marijuana users report the effects of withdrawal when they stop or cut back.

10) Keep in mind that there is a separate charge for testing. At MCR Labs in Framingham, for instance, testing one sample is $70. Three or more are $50 each.