Blood tests, as opposed to urinalysis, identify the active presence of THC in the bloodstream. THC levels, for example, peak quickly after smoking cannabis and begin to fall within an hour. As a result, high THC levels in the blood are a good indicator that you have recently smoked. Blood tests can also detect the presence of other drugs, such as alcohol or cocaine. Alcohol increases THC's effects by slowing down the body's natural response time, while cocaine blocks THC's effect on the brain and causes its own effects to dominate.
Cannabis' primary active ingredient is THC. The amount of THC in each marijuana plant varies depending on the type of strain, but most plants will contain between 3% and 20% THC. When smoked, THC stimulates certain receptors in the brain that produce the drug's psychotropic effects. The higher the percentage of THC, the stronger the dose will be. Plants with higher amounts of total cannabinoids (including CBD) may still make sense medically, but they will also be more potent emotionally and physically.
The main way people consume marijuana today is by smoking it. When you smoke cannabis, THC is absorbed into the blood stream immediately. This means that you will feel its effects soon after you inhale. Since THC is fat-soluble, it will also be stored in the fat cells of your body. So even if you stop smoking right now, you would still be able to feel the effects of marijuana use later in the day.
THC concentrations in blood plasma typically exceed 100 ng/ml in the first few minutes after inhaling smoked marijuana. It then swiftly drops to single digits within an hour. There are several factors that can affect how quickly you feel the effects of THC: the amount you smoke, the quality of the product, and your body weight.
When you smoke marijuana, you expose your lungs to toxic chemicals that aren't present when you ingest the drug in another form, such as a capsule or tincture. Your body is also less able to break down THC when it's administered this way, so it remains in your bloodstream for longer. Heavy smokers may need more frequent doses of medicine over time if they don't want to experience a buildup of THC in their system.
People who are obese may require higher doses of medication than those who are not fat enough. The more muscle you have, the more THC you can tolerate without getting high.
The best strategy for avoiding a buildup of THC is to reduce your usage if you're a heavy smoker. If you cannot stop smoking completely, try to limit yourself to no more than one or two cigarettes per day. This will help prevent high levels of THC from occurring too frequently. As long as you keep your consumption below three hits per day, you should be fine.
Weed (i.e., THC) specifically remains in the blood for one to two days following a single usage. Weed will persist in your blood for up to a week after your previous session if you smoke several times or consistently, or multiple times everyday. C-9 acetylation can also slow the elimination of THC from the body, so even if you stop smoking now, the drug will still be present in your bloodstream for some time.
When you use marijuana daily over a period of months or years, your body gets used to it and requires more frequent doses to achieve the same effect. Users who report daily or near-daily use of marijuana have been found to require doses about 10% larger than those observed among monthly users to achieve the same level of intoxication.
The average dose of THC needed to produce a psychoactive effect in a daily user is about 3 mg/kg of body weight; for example, this means that if you weigh 70 kg (154 pounds), you should aim to consume 70 kg x 3 mg/kg = 210 mg of THC to be affected by it. For comparison, a standard dose of THC for someone who doesn't use daily is around 5 mg. Daily users therefore need about 50% more THC than people who don't use the drug daily to reach the same effect.