There are two conversations about safety in Colombia that are both useless. The first one is your aunt forwarding you a State Department travel warning. The second is the expat in El Poblado telling you it's "super safe now, bro, don't worry about it." Neither is giving you actionable information.
What follows is what I'd tell a friend who's actually going: honest, specific, and without the editorial agenda that comes with either extreme.
The baseline reality
Colombia has significantly improved in safety over the past two decades. The peak of narco violence in the 1990s, the Medellín Pablo Escobar era, is genuinely historical. The murder rate in Medellín today is comparable to, or better than, many major US cities. The transformation is real, documented, and not marketing.
At the same time: Colombia is not Switzerland. Petty theft is common in most cities. There are neighborhoods in every major city where the risk of violent crime is real, not theoretical. Certain regions of the country outside the main cities have active conflict zones. Dismissing the risk entirely is as misleading as exaggerating it.
The goal is calibrated awareness, not paranoia and not willful blindness. The same judgment you'd apply in any large city in a developing country.
City by city
Medellín: The tourist areas, El Poblado, Laureles, Envigado, are genuinely safe for the normal exercise of caution. Don't flash expensive electronics, don't wander into unfamiliar neighborhoods at 2am, use apps instead of street taxis at night. The hillside comunas are mostly fine during the day with a guide, less so at night solo. Beyond those specific areas, use judgment.
Bogotá: Bigger city, wider range. Chapinero and Usaquén are comfortable. La Candelaria is fine during daylight hours and rough after dark. The TransMilenio buses are notorious for pickpocketing, keep your phone in a front pocket, not your back pocket, and be aware on crowded carriages. The risk in Bogotá is mostly theft, not violence, in the areas tourists visit.
Cartagena: The tourist zones (Walled City, Getsemaní) are fine but pick your moments. The influx of cruise ship tourists has made the Walled City a target for hustlers and scammers. Getsemaní at 3am when you've had a few is a different calculus than Getsemaní at 9pm for dinner. The city outside the tourist zones has a different risk profile.
Cali: More real safety considerations than Medellín or Cartagena in the tourist zones. El Peñón and Granada are the areas to stay in. Centro is a daytime-only zone, and even then with awareness. Carry less cash here than in other cities. The safety situation in Cali is real but manageable with basic precautions, don't let it stop you from going.
Santa Marta and the coast: The tourist areas are fine. Palomino is mellow. Tayrona requires standard rural awareness (don't hike alone, leave valuables at your accommodation). The interior of the city of Santa Marta gets rougher after dark.
The scopolamine thing
Scopolamine (also called burundanga) is a real drug used in Colombia for robbery. It can be administered in drinks or even, reportedly, through paper. The risk is concentrated in certain contexts: accepting drinks from strangers, going home with people you just met, taking drugs from people you don't know. If you're exercising normal social caution, the risk is low. If you're getting blackout drunk in sketchy bars and accepting things from strangers, it's higher.
The stories that circulate online are usually about people who made multiple compounding bad decisions in a row. Don't make those decisions and you're probably fine. Be aware it exists.
Taxis and transport
This is the most important practical safety point: do not take unmarked taxis off the street in any major Colombian city. Express kidnapping via fake taxis is real. Use InDriver, Cabify, or have your accommodation call a trusted taxi. The apps are cheap, the ride is trackable, and this single habit eliminates a significant category of risk.
Uber technically operates in a grey area in Colombia but functions well in practice. Cabify is fully legal and works the same way. Either is fine. The point is: app-booked, not flagged-from-the-street.
What to leave at home
Expensive-looking jewelry. Your passport (carry a photocopy; leave the original in your accommodation safe). More cash than you need for the day. Your newest, shiniest phone held openly in your hand on the street. None of this is Colombia-specific, it's basic urban travel advice that applies here more than in some places.
The neighborhood question
Every major Colombian city has clear geographic zones of risk. The good news: these zones are well-known and easy to avoid. The bad news: some travelers don't bother to find out where they are.
Before going anywhere outside the obvious tourist zones, do thirty seconds of research or ask your accommodation. The staff at any decent hostel or hotel will tell you exactly what to know, without drama or exaggeration, because they deal with this question every day. Ask the people who live there.
The honest summary
Colombia can be traveled safely and comfortably with normal urban awareness. Most people who visit never have any incident beyond something that could happen in any city in the world. The transformation of the past two decades is real.
And: it is not a zero-risk destination. Don't let the expat bubble convince you otherwise. The risks are real, specific, and mostly avoidable with basic precautions. Know them. Respect them. Then go and have a good time.
The country is worth it. I wouldn't be living here if it weren't.