Routes of Administration

How drugs enter your body — and why the same substance can be dramatically more dangerous depending on how it's taken.

Faster onset = more intense rush = shorter duration = higher addiction potential = higher overdose risk. This isn't a moral judgment — it's pharmacokinetics.

Oral (Swallowing)

PO, ingestion, eating, parachuting

Risk 1/8

Stomach/intestine → hepatic portal vein → liver (processes some of the drug) → systemic circulation → brain

🚀 20–90 minBioavailability: 30–70% typicalProcessed by liver first

Short-term risks

• Nausea/vomiting

• Slow unpredictable onset → impatient redosing → accidental overdose

• Food in stomach changes absorption

Long-term risks

• GI irritation/ulceration

• Liver strain

• Tooth enamel erosion

Sublingual / Buccal

Under the tongue, against the cheek

Risk 2/8

Oral mucosa → bloodstream (skips liver entirely)

🚀 2–15 minBioavailability: Higher than oral for many substancesSkips liver processing

Short-term risks

• Extremely bitter taste

• Local numbness/irritation

• Swallowing saliva redirects dose to oral route

Long-term risks

• Oral mucosa erosion with repeated use

• Dental issues

Common for LSD (blotter), buprenorphine (Suboxone), some benzos.

Insufflation (Snorting)

Intranasal, sniffing, railing, bumping

Risk 3/8

Nasal mucous membrane → bloodstream → brain. Part of dose drips to stomach (oral absorption).

🚀 2–15 minBioavailability: 30–80%Skips liver processing

Short-term risks

• Nosebleeds

• Burning/congestion

• Post-nasal drip (nausea, bad taste)

• Sharing straws/notes transmits Hepatitis C via microscopic blood

Long-term risks

• Chronic sinusitis

• Loss of smell (anosmia)

• Nasal septum perforation

• Saddle nose deformity

• Palatal perforation (rare, primarily cocaine)

Vasoconstrictive substances restrict blood flow → oxygen starvation → tissue death → perforation.

Rectal (Plugging)

Boofing, plugging, booty bumping

Risk 4/8

Rectal mucosa → bloodstream. Lower ⅔ skips the liver; upper ⅓ gets processed by liver first.

🚀 5–15 minBioavailability: Generally higher than oralLiver processes ~⅓ of dose

Short-term risks

• Rectal mucosal irritation/damage

• Difficulty controlling dose

• Overdose risk from high bioavailability

Long-term risks

• Chronic mucosal inflammation

• Increased STI/HIV risk (tears create entry points)

Legitimate medical route — suppositories used for anti-nausea meds, seizure medication, pain relief.

Inhalation — Vaporizing

Vaping, freebasing

Risk 5/8

Heated below combustion → vapor → lungs (70m² surface, 0.5μm barrier) → pulmonary veins → brain

🚀 5–20 secondsBioavailability: Highly variable by technique. Higher than smoking.Skips liver processing

Short-term risks

• Burns (improvised devices)

• Chest tightness

• Very fast onset → intense rush → strongest redosing drive

Long-term risks

• Chronic respiratory irritation

• Reduced lung capacity

• Unknown long-term for newer devices

Produces drug effect with dramatically fewer toxic byproducts than combustion. Harm reduction orgs recommend vaporizing over smoking.

Inhalation — Smoking

Combustion, chasing (heating on foil)

Risk 6/8

Same lung absorption as vaporizing, BUT combustion adds tar, carbon monoxide, and carcinogens

🚀 5–20 secondsBioavailability: Variable, often lower than vaporizingSkips liver processing

Short-term risks

• All vaporizing risks PLUS toxic combustion byproducts

• Burns from foil/pipes

Long-term risks

• Cancer risk (from combustion, not the drugs)

• Chronic bronchitis

• Crack lung (smoked cocaine)

• All vaporizing long-term risks

Route transitioning from injection to smoking is an established harm reduction strategy.

Transdermal (Patches)

Patches, topical absorption

Risk 2/8

Drug in adhesive matrix → absorbed through skin → capillaries in dermis → systemic circulation

🚀 1–6 hoursBioavailability: Variable. Fentanyl patch ~92% over 72hr. Nicotine patch ~75–80%.Skips liver processing

Short-term risks

• Skin irritation

• Slow onset (low abuse potential as designed)

Long-term risks

• Contact dermatitis at application sites

DANGER: Heat dramatically accelerates fentanyl patch absorption → overdose deaths. Cutting patches causes dose dumping. Used patches still contain significant residual drug.

Intramuscular Injection (IM)

Muscle shot, IM

Risk 5/8

Injected into muscle tissue → absorbed through capillary beds → systemic circulation → brain

🚀 5–20 minBioavailability: ~75–100%Skips liver processing

Short-term risks

• Injection site pain/swelling

• Abscess if technique is poor

• Nerve damage (incorrect site)

Long-term risks

• Muscle fibrosis/scarring with repeated use

• Bloodborne infections from shared equipment

• Sterile abscesses

Common medical route (vaccines, ketamine clinics). Slower onset than IV reduces overdose risk but also reduces ability to titrate dose. Same sterile equipment rules apply — syringe service programs provide supplies.

Intravenous Injection (IV)

Shooting, slamming, mainlining, fixing

Risk 8/8

Dissolved in liquid → injected into vein → immediate systemic circulation → brain in ~15–30 seconds

🚀 15–30 secondsBioavailability: 100% (by definition)Skips liver processing

Short-term risks

• Overdose (entire dose hits at once — no buffer)

• Arterial injection (medical emergency)

• Air embolism

• Injection site infections/abscesses

Long-term risks

• Vein collapse/sclerosis

• Bloodborne infections: HIV, Hepatitis B, Hepatitis C

• Endocarditis (heart valve infection)

• Sepsis

• Strongest conditioning loop for dependence

Syringe service programs provide sterile equipment. Never Use Alone (1-800-484-3731) — stays on the line during use.

Liver Processing ("First-Pass")

When you swallow a drug, it travels through the digestive system to the liver before reaching your brain. The liver breaks down a fraction of the drug before it ever arrives — pharmacologists call this "first-pass metabolism." Routes that skip the liver (snorting, smoking, injection, sublingual, rectal) deliver more of the dose to your brain. This is why the same amount of a drug can be much more potent through a non-oral route.

Bioavailability

The percentage of a dose that reaches your bloodstream in active form. IV injection = 100% by definition. Everything else is less. Why this matters: if you switch routes without adjusting your dose, you can accidentally give yourself a much larger effective dose. Route-switching without dose adjustment is a common cause of overdose death.

Speed-to-Brain Comparison

Route	Onset	Why
IV injection	15–30 sec	Direct into bloodstream → brain in one cardiac cycle
Inhalation (smoking/vaping)	5–20 sec	Lungs → heart → brain. 70m² absorptive surface.
Insufflation (snorting)	2–15 min	Nasal mucosa → bloodstream
Sublingual/buccal	2–15 min	Oral mucosa → bloodstream
Rectal (plugging)	5–15 min	Rectal mucosa → bloodstream. ⅔ skips the liver.
IM injection	5–20 min	Muscle capillaries → bloodstream
Transdermal (patch)	1–6 hr	Skin dermis → capillaries. Designed for slow release.
Oral (swallowing)	20–90 min	GI absorption → liver processes some of the drug → bloodstream