Opioids are taken in several ways depending on the type of pain, how quickly relief is needed, and whether the medication is for short-term or ongoing use. The most common route is by mouth as a pill or liquid, but opioids can also be absorbed through the skin, dissolved under the tongue, placed inside the cheek, injected, or delivered through the nose. Each method reaches the bloodstream differently, which changes how fast the drug works and how long its effects last.
Oral Pills and Liquids
Swallowing a pill or liquid is the most widely used method. When you take an opioid by mouth, it passes through your digestive system and liver before entering your bloodstream. This “first pass” through the liver breaks down a significant portion of the drug before it ever reaches the rest of your body. Fentanyl, for example, loses about 70% of its potency when swallowed, which is why oral fentanyl is rarely prescribed in pill form.
Oral opioids come in two main designs: immediate-release and extended-release. The difference matters because it determines how often you take them and how the drug behaves in your body.
Immediate-Release Formulations
Immediate-release opioids deliver their full dose quickly, typically within 15 to 30 minutes, and wear off in a few hours. They need to be taken every 4 to 6 hours to maintain pain relief, which creates peaks and valleys in blood levels throughout the day. These are usually prescribed on an as-needed basis for acute pain, like after surgery or an injury. A common example is a hydrocodone/acetaminophen tablet taken no more than every four hours.
Extended-Release Formulations
Extended-release opioids use a special coating or matrix that slowly releases the medication over many hours. This keeps blood levels more stable, with fewer spikes and dips. Depending on the specific product, dosing ranges from twice daily to once a week. Extended-release morphine capsules, for instance, can be taken once or twice daily, while certain transdermal patches last a full seven days. These formulations are reserved for severe, continuous pain and are not meant to be taken on an as-needed basis.
One critical rule with extended-release tablets and capsules: they must be swallowed whole. Crushing, chewing, splitting, or dissolving them defeats the slow-release mechanism and dumps the entire dose into your system at once. This can cause life-threatening breathing problems, overdose, and death.
Skin Patches
Transdermal patches stick to the skin and deliver a steady, low dose of opioid through the skin’s surface into the bloodstream. Fentanyl patches release medication at a constant rate for two to three days before needing replacement. Buprenorphine patches last a full week. Because the drug bypasses the digestive system entirely, patches avoid the first-pass metabolism that reduces oral potency.
Patches take longer to reach full effect compared to pills, sometimes several hours, which makes them unsuitable for sudden or rapidly changing pain. They’re designed for people with stable, around-the-clock pain who need consistent relief without repeated dosing. The patch is applied to a flat, clean area of skin, typically on the chest, back, or upper arm, and rotated to a new site with each change.
Under the Tongue and Inside the Cheek
Some opioids are designed to dissolve in the mouth rather than be swallowed. Sublingual formulations go under the tongue, while buccal formulations are pressed against the inside of the cheek. Both routes allow the drug to absorb directly through the thin, blood-vessel-rich tissue of the mouth and into circulation.
For sublingual films, you rinse your mouth with water first, place the film under your tongue with a dry finger to the left or right of center, and hold it for five seconds. Buccal films work similarly but go against the inner cheek. In both cases, you leave the film in place until it dissolves completely without chewing, touching, or moving it, and you avoid eating or drinking until it’s fully absorbed. If two films are needed, they go on opposite sides of the mouth and should never be stacked on top of each other.
Oral transmucosal delivery can work remarkably fast. Fentanyl lozenges and films absorbed through the mouth lining reach peak blood levels in about 20 minutes, with some formulations producing noticeable relief within 5 minutes. This makes them useful for breakthrough pain episodes that flare up despite a baseline pain regimen.
Nasal Sprays
Intranasal opioids are sprayed into the nose, where the drug absorbs through the nasal lining. This is the fastest non-injectable route. Nasal fentanyl reaches peak blood levels in roughly 12 minutes, with pain relief beginning in as little as 2 minutes. The nose’s rich blood supply and thin tissue allow rapid absorption without passing through the liver first.
Injection
In medical settings, opioids can be delivered by injection under the skin (subcutaneous), into a muscle (intramuscular), or directly into a vein (intravenous). Intravenous delivery is the fastest of all routes because the drug enters the bloodstream immediately, bypassing every barrier. This method is common in hospitals for surgical pain, severe injuries, and palliative care. When a patient can no longer take medications by mouth, subcutaneous and intravenous routes are generally preferred.
How the Route Affects Dosing
The same opioid can require very different doses depending on how it’s taken. Because oral medications lose potency during digestion, an oral dose is typically much higher than what would be given intravenously. A transdermal patch, by contrast, uses a tiny amount of a very potent drug delivered continuously. This is why opioid prescriptions are not interchangeable between routes without careful dose conversion by a clinician.
Current prescribing guidelines recommend starting at the lowest effective dose for anyone not already on opioids, typically equivalent to about 5 to 10 milligrams of morphine per single dose or 20 to 30 milligrams per day. Immediate-release formulations are preferred as a starting point, with extended-release versions reserved for patients whose pain is severe and constant.
Safe Storage and Disposal
Unused opioids in any form, whether pills, patches, or syrups, pose a risk to children, pets, and others in the household. The safest disposal method is a drug take-back location, such as a medicine drop-off box at a local pharmacy or a prepaid mail-back envelope program. If no take-back option is available, the FDA maintains a “flush list” of opioids that should be flushed down the toilet rather than left in the trash, specifically because accidental exposure to these medications can be fatal. Opioids not on the flush list can be mixed with coffee grounds or kitty litter, sealed in a container, and thrown away.
Naloxone: Reversing an Overdose
Naloxone is not an opioid, but it’s directly tied to how opioids are taken because it temporarily blocks their effects during an overdose. The nasal spray version is available without a prescription and designed for bystanders to use. Each device contains a single dose: you peel open the packaging, insert the nozzle into one nostril, and press the plunger. No priming or testing is needed.
The reversal is temporary. Naloxone wears off faster than most opioids, which means overdose symptoms can return after the naloxone fades. Emergency medical help should be called immediately after the first dose, even if the person appears to recover.