Colchicine (low-dose, cardiovascular prevention)

What colchicine is

Colchicine is an alkaloid of the autumn crocus and has long been used against gout and pericarditis. What is new is its use at a low dose to prevent heart attack and stroke, not as a replacement for cholesterol-lowering drugs such as statins, but in addition to them.

The idea behind it: atherosclerosis is not only a question of cholesterol, but also of inflammation. Even people whose LDL is well controlled retain a residual risk, and this is where colchicine comes in. In the biohacking context it is thus close to questions such as aspirin prevention.

How it works

Colchicine inhibits the assembly of microtubules, the internal scaffold of cells. In inflammatory cells, this slows the migration of granulocytes into inflamed tissue and the activation of the NLRP3 inflammasome, a molecular switch that drives inflammation in vascular plaques. This is measurable in the inflammation marker CRP, which falls under colchicine.

The EU product information is cautious: the exact mechanism of the cardioprotective effect has not been clarified. It is assumed that the dampened vascular inflammation lowers the residual risk that remains despite optimal standard therapy.

What the studies show

COLCOT 2019: after the heart attack

Patients were randomized within 30 days after a heart attack to 0.5 mg of colchicine daily or placebo and followed for a median of 22.6 months. The composite endpoint fell from 7.1 to 5.5 percent (HR 0.77). This was driven mainly by strokes (HR 0.26) and urgent hospitalizations for angina leading to revascularization (HR 0.50); cardiovascular death and heart attack alone did not differ significantly. Pneumonia as a serious side effect was more common under colchicine (0.9 versus 0.4 percent).

LoDoCo2 2020: chronic coronary heart disease

5,522 patients with stable coronary heart disease received 0.5 mg of colchicine or placebo, median 28.6 months. The primary endpoint occurred in 6.8 versus 9.6 percent (HR 0.69), corresponding to 2.5 versus 3.6 events per 100 person-years. Deaths from non-cardiovascular causes tended to be more common under colchicine (HR 1.51; 0.99 to 2.31). The EU product information refers to this trial.

CLEAR 2025: no benefit directly after the heart attack

The largest trial to date, CLEAR, also known as CLEAR SYNERGY, randomized 7,062 patients soon after a heart attack to colchicine or placebo, median 3 years. The endpoint of cardiovascular death, recurrent heart attack, stroke and unplanned revascularization occurred in 9.1 versus 9.3 percent (HR 0.99). CRP fell, the events did not; diarrhea was more common (10.2 versus 6.6 percent), serious infections were not.

CONVINCE 2024: narrowly missed after stroke

3,154 patients after non-cardioembolic stroke or high-risk TIA received colchicine in addition or usual care only, open-label with blinded endpoint assessment. Events occurred in 9.8 versus 11.7 percent (HR 0.84; p = 0.12). The trial was ended before reaching the planned number of events because of budget problems during the pandemic; the authors nevertheless see the inflammation hypothesis as supported.

Where the data stop

• A benefit directly after the heart attack. COLCOT was positive, the larger trial CLEAR was not. In which phase after a heart attack colchicine helps is therefore open; the EU approval applies only from 6 months of stable disease.
• A benefit after stroke. CONVINCE narrowly missed its goal and was ended early. There is no approval for this group.
• Longer life. Neither the individual trials nor the meta-analysis show lower all-cause mortality; in LoDoCo2 there was even a signal for more non-cardiovascular deaths.
• A benefit for healthy people. All endpoint data come from people with heart or vascular disease. For people without this history there is no trial that shows an advantage.

Status, approval and legal

In the EU, Colchicin AGEPHA Pharma 0.5 mg has been approved since 24.07.2026, for the secondary prevention of atherothrombotic events in adults with coronary heart disease that has been stable for at least 6 months. The approved dose is 0.5 mg once daily, which is also the maximum dose. The approval also applies in Germany; colchicine is prescription-only.

In the US, Lodoco has been approved since June 2023 to reduce heart attack, stroke, revascularization and cardiovascular death in adults with established atherosclerosis or multiple risk factors. Use in healthy people without cardiovascular disease is not provided for in either approval.

Safety

At the low dose, colchicine was mostly well tolerated in the large trials; diarrhea was somewhat more common than under placebo. In COLCOT, serious pneumonia occurred more often (0.9 versus 0.4 percent); in LoDoCo2 there tended to be more non-cardiovascular deaths.

The narrow therapeutic index is important. According to the EU product information, an overdose can lead to multi-organ failure; the first signs are diarrhea, nausea and vomiting. Colchicine must not be combined with strong CYP3A4 or P-glycoprotein inhibitors, and it is contraindicated with an eGFR below 50 ml/min, severe liver dysfunction and pre-existing blood count abnormalities. Together with statins and fibrates, the risk of muscle damage up to rhabdomyolysis increases. Women of childbearing age must use reliable contraception; men must not father a child during treatment and for up to 3 months afterwards.

Sources

• Tardif JC et al., N Engl J Med 2019 – COLCOT, 0.5 mg colchicine after heart attack, 4,745 patients
• Nidorf SM et al., N Engl J Med 2020 – LoDoCo2, 0.5 mg colchicine in chronic coronary heart disease, 5,522 patients
• Jolly SS et al., N Engl J Med 2025 – CLEAR (CLEAR SYNERGY), colchicine directly after heart attack, 7,062 patients, no benefit
• Kelly P et al., Lancet 2024 – CONVINCE, colchicine after stroke or TIA, 3,154 patients
• Cueva-Cañola LE et al., Med Clin (Barc) 2026 – meta-analysis, 39 RCTs with 37,812 participants on colchicine in cardiovascular disease
• FDA, approval letter NDA 215727 – Lodoco (colchicine 0.5 mg), June 2023
• EMA – Colchicine AGEPHA Pharma, European public assessment report, EU approval 24.07.2026
• EMA – Colchicin AGEPHA Pharma 0.5 mg tablets, product information (German)
• German Prescription Drugs Ordinance (AMVV), Annex 1 – colchicum alkaloids prescription-only