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Signs of teen drug use: What parents need to know

Published October 4, 2024 · 8 min read · Updated April 2026

Reviewed for accuracy by licensed clinical professionals.

Recognizing teen drug use early enables intervention before addiction develops. Many signs overlap with normal adolescent behavior, but patterns matter.

Physical signs

Bloodshot eyes. Sudden weight changes. Unusual smells on breath or clothing. Frequent nosebleeds. Changes in appetite or sleep. Deteriorating physical appearance.

Behavioral signs

Declining grades. New friend group. Withdrawal from family. Loss of interest in activities. Mood swings beyond normal teen range. Secretiveness about phone and social media. Money or valuables missing.

How to respond

Stay calm. Have a conversation, not a confrontation. Express concern without accusation. Listen. Do not overreact to experimentation but take patterns seriously. Professional evaluation if concerned. Family therapy can help.

Authoritative sources

This article references guidelines from: NIDA · SAMHSA · CDC

Frequently asked questions

How do I know if my teenager is using drugs?

Look for patterns of physical changes, behavioral shifts, new friends, declining grades, and secretiveness.

Should I drug test my teenager?

Testing can provide information but damages trust. Consider whether the information is worth the relationship impact.

What do I do if my teen is using drugs?

Stay calm. Express concern. Listen. Seek professional evaluation. Family therapy can address underlying issues.

Disclaimer: Informational only. Not medical advice. SAMHSA: 1-800-662-4357.