Alirocumab is an injectable cholesterol drug that lowers LDL by roughly half to 60% on top of a statin, far more than any pill can, by blocking a protein called PCSK9. Most people end up on it because their LDL is still too high despite a statin (often plus Ezetimibe) and they need a much bigger lever, or they genuinely can't tolerate statins and need strong LDL lowering without them. It's also used for inherited high cholesterol (familial hypercholesterolemia), where LDL runs high from birth. It's sold as Praluent, given as a self-injection every two weeks or once a month.

This is one of the few lipid drugs with hard outcome data behind it, not just a number on a lab report. In people who recently had a heart attack or unstable angina, it cuts the risk of further heart attacks and strokes, and it's one of the only LDL-lowering drugs of its kind to also show a reduction in death from any cause. You won't feel anything taking it, the effect is entirely on your bloodwork and your long-term risk, and it's well tolerated. The main practical downsides are that it's an injection and it's expensive.

Deep-dive

Dosage:

• Two starting options: 75 mg every 2 weeks, or 300 mg once monthly (given as two 150 mg injections). The 75 mg dose is enough for most people, in the phase 3 program around three quarters reached their LDL target on it. If LDL is still too high after about 8 weeks, the dose goes up to 150 mg every 2 weeks, which is also the standard starting dose for inherited high cholesterol where a bigger drop is needed from the outset
• Given as a subcutaneous self-injection, into the abdomen, thigh, or back of the upper arm. It comes as a prefilled pen or syringe
• Rotate injection sites and don't inject into skin that's bruised, red, tender, or hard. Let the pen warm to room temperature before injecting, it stings less and is more comfortable
• alirocumabIt's almost always an add-on, not a replacement. Keep your statin (and ezetimibe, if you're on it) going, stacks on top. The exception is genuine statin intolerance, where it's used without a statin
• Give it 4-8 weeks before checking a lipid panel. The LDL effect shows up fast but you want a stable read before deciding whether to up-titrate. The 8-week check is the standard decision point for moving from 75 mg to 150 mg
• Same dose regardless of sex, age, body weight, or mild-to-moderate kidney or liver function. No adjustment needed. It is approved down to age 8 for inherited high cholesterol, which is rare for a lipid drug
• Storage matters: it's a biologic, keep it refrigerated. It can sit at room temperature but only for a limited window, then it has to be discarded
• This is a long-term drug. LDL returns to baseline within weeks of stopping, the same way it does with statins, so it's only worth taking if you plan to stay on it

Here's what you can expect:

You will not feel anything. Alirocumab has no perceptible day-to-day effect, no energy change, nothing you'd notice. The only evidence it's working is a blood test, and on that test the change is dramatic: LDL down by roughly half to 60%, showing up within the first few weeks and stable from then on.

The thing you might notice is at the injection site, mild redness, an itch, or tenderness for a day or so. It's the most common real effect and usually fades as you get used to the technique.

Everything else is invisible and long-term: a lower heart attack and stroke risk that compounds the longer you stay on it. This is a number-mover and a risk-mover, not something you experience.

Side effects & risks: