RE: Does anyone know (science question)19 Jan 2026 18:02
Thorn, I know if I have a sip of wine or a mouthful of beer on an empty stomach it's only scores of seconds before I first feel it. Inspired by this I've consulted AI on 'the time it takes drugs to circulate the body':
'Once a drug is absorbed into the bloodstream, it circulates throughout the body extremely fast, as the average circulation time of blood is
roughly 1 minute.
While the blood moves quickly, the time it takes for a drug to reach its target site and produce an effect depends largely on the route of administration, ranging from seconds to several hours.
Key Factors Influencing Speed of Circulation/Effect
Intravenous (IV) Injection: The fastest route, delivering drugs immediately to the bloodstream, often taking effect in seconds to minutes.
Inhalation: Also very fast, with effects in a matter of minutes.
Oral Medication (Pills): Generally takes 30 to 90 minutes to reach peak concentration in the blood, as the drug must first dissolve and be absorbed through the stomach or intestinal walls.
Intramuscular/Subcutaneous Injection: Usually takes a few minutes to be absorbed, depending on local blood flow.
Important Considerations
First-Pass Metabolism: Orally taken drugs must first pass through the liver, which can slow down or reduce the amount of active drug reaching the general circulation.
Distribution Factors: Highly lipid-soluble (fat-soluble) drugs can cross cell membranes quickly, while water-soluble drugs tend to stay within the blood and fluids surrounding cells.
Accumulation: Some drugs accumulate in tissues (like fat) and are released slowly, causing them to stay in the body for days or longer after use has stopped.
Drug Half-Life: This measures how quickly a drug is eliminated from the body. It generally takes 4 to 5 half-lives for a drug to be considered effectively cleared from the system.'