What Is Lovenox?

Lovenox is the brand name for Enoxaparin Sodium, a low molecular weight heparin (LMWH) anticoagulant manufactured by Sanofi-Aventis. It is an injectable blood thinner used to prevent and treat dangerous blood clots.

Lovenox is FDA-approved for:

• Prevention of deep vein thrombosis (DVT) after hip or knee replacement surgery
• Prevention of DVT after abdominal surgery in at-risk patients
• Treatment of acute DVT with or without pulmonary embolism (PE)
• Prevention of blood clot complications in unstable angina and certain heart attacks (used with Aspirin)
• Treatment of acute ST-segment elevation myocardial infarction (STEMI)

It is also commonly used off-label as bridge therapy for patients on Warfarin undergoing surgery, for VTE prophylaxis in hospitalized medical patients, and as the preferred anticoagulant during pregnancy.

How does Lovenox work?

Lovenox works by binding to and activating antithrombin III, a natural protein in your blood that helps regulate clotting. Once activated, antithrombin III primarily inhibits Factor Xa — a key enzyme in the blood clotting cascade — and to a lesser extent Factor IIa (thrombin). By blocking these clotting factors, Lovenox interrupts the coagulation process and prevents new blood clots from forming.

Unlike unfractionated Heparin, Lovenox has a more predictable dose-response relationship and longer half-life, which means it can be given as a once- or twice-daily subcutaneous injection without routine blood monitoring in most patients.

What doses are available for Lovenox?

Lovenox (Enoxaparin Sodium) is available as prefilled syringes for subcutaneous injection and a multi-dose vial:

• 30 mg/0.3 mL prefilled syringe
• 40 mg/0.4 mL prefilled syringe
• 60 mg/0.6 mL prefilled syringe
• 80 mg/0.8 mL prefilled syringe
• 100 mg/1 mL prefilled syringe
• 120 mg/0.8 mL prefilled syringe
• 150 mg/1 mL prefilled syringe
• 300 mg/3 mL multi-dose vial (100 mg/mL)

Your prescribed dose depends on your condition, body weight, and kidney function. DVT prophylaxis typically uses 30 mg or 40 mg doses, while treatment doses are weight-based (1 mg/kg).

How hard is it to find Lovenox in stock?

Lovenox (Enoxaparin Sodium) scores a 65 out of 100 on our findability scale, meaning it can be intermittently difficult to locate. While generic Enoxaparin is widely manufactured, certain prefilled syringe strengths — particularly the 40 mg and 60 mg doses — have experienced periodic shortages since 2019 due to manufacturing disruptions at key generic producers. Brand-name Lovenox from Sanofi is generally more consistently stocked but comes at a significantly higher price. If your local pharmacy is out, try calling specialty pharmacies, hospital outpatient pharmacies, or use Medfinder to locate it in stock near you.

Who Can Prescribe Lovenox?

Lovenox is prescribed by a wide range of medical specialists, including:

• Hematologists — for blood clot disorders and thrombophilia management
• Cardiologists — for heart attack treatment and prevention of cardiac clot complications
• Orthopedic Surgeons — for DVT prevention after hip and knee replacement
• General Surgeons — for post-operative VTE prophylaxis
• Hospitalists / Internal Medicine — for inpatient DVT prevention and treatment
• OB/GYN specialists — for anticoagulation during pregnancy
• Oncologists — for cancer-associated VTE prevention and treatment
• Emergency Medicine physicians — for acute DVT/PE treatment
• Primary Care providers — for outpatient DVT treatment and bridge therapy

Is Lovenox a controlled substance?

No. Lovenox (Enoxaparin Sodium) is not a controlled substance and has no DEA scheduling. It does not carry a risk of abuse or dependence. However, it is a prescription-only medication that requires a doctor's order. Because it is an injectable anticoagulant with a risk of serious bleeding, it should only be used under medical supervision.

Common Side Effects of Lovenox

Like all anticoagulants, Lovenox carries a risk of side effects. Most are mild, but some can be serious.

Common side effects:

• Injection site bruising, pain, redness, or irritation
• Mild bleeding or easy bruising
• Nausea
• Fever
• Peripheral edema (swelling)
• Mild anemia
• Elevated liver enzymes (AST/ALT)

Serious side effects (seek immediate medical attention):

• Major hemorrhage (GI bleeding, intracranial bleeding)
• Heparin-induced thrombocytopenia (HIT) — a dangerous drop in platelets
• Spinal or epidural hematoma (especially with neuraxial anesthesia) — can cause permanent paralysis
• Retroperitoneal bleeding
• Severe allergic reactions or anaphylaxis
• Hyperkalemia (elevated potassium)
• Osteoporosis with long-term use

Black Box Warning: Patients receiving Lovenox who undergo spinal/epidural anesthesia or spinal puncture are at risk for epidural or spinal hematomas that can result in long-term or permanent paralysis. This risk increases with indwelling epidural catheters, concomitant use of NSAIDs or antiplatelet drugs, and traumatic or repeated punctures.

Alternative Medications to Lovenox

If Lovenox is unavailable or not suitable for you, your doctor may consider these alternatives:

• Heparin (Unfractionated) — IV or subcutaneous anticoagulant that is fully reversible with protamine; used primarily in hospital settings and requires aPTT monitoring
• Fondaparinux (Arixtra) — A synthetic Factor Xa inhibitor given as a once-daily subcutaneous injection; a good option for patients with a history of heparin-induced thrombocytopenia (HIT)
• Dalteparin (Fragmin) — Another low molecular weight heparin with similar efficacy to Enoxaparin; preferred in some cancer-related VTE treatment guidelines
• Rivaroxaban (Xarelto) — An oral direct Factor Xa inhibitor that eliminates the need for injections; widely used for DVT/PE treatment and prevention
• Apixaban (Eliquis) — Another oral Factor Xa inhibitor commonly used for DVT/PE treatment as an alternative to injectable anticoagulants
• Warfarin (Coumadin) — Oral anticoagulant often used long-term after initial Enoxaparin treatment; requires regular INR monitoring

Always consult your doctor before switching anticoagulants, as each has different monitoring requirements, reversal options, and risk profiles.

Drug Interactions with Lovenox

Lovenox can interact with several medications, primarily those that also affect bleeding:

Major interactions (increased bleeding risk):

• Warfarin and other oral anticoagulants
• Antiplatelet agents — Aspirin, Clopidogrel (Plavix), Prasugrel, Ticagrelor
• NSAIDs — Ibuprofen, Naproxen, Ketorolac (especially Ketorolac)
• Thrombolytics — Alteplase (tPA), Tenecteplase — significantly increases bleeding risk
• Other heparins or heparinoids — should not be used together

Moderate interactions:

• SSRIs and SNRIs (antidepressants) — may increase bleeding tendency
• Fish oil / Omega-3 supplements — may increase bleeding risk
• Ginkgo biloba — may increase bleeding risk
• Dipyridamole — increased hemorrhagic risk

Always inform your doctor and pharmacist of all medications, supplements, and herbal products you are taking before starting Lovenox.

Final Thoughts on Lovenox

Lovenox (Enoxaparin Sodium) remains one of the most widely prescribed injectable anticoagulants for preventing and treating blood clots. While generic Enoxaparin has made it more affordable, intermittent shortages of certain syringe strengths can make it challenging to find — particularly the 40 mg and 60 mg prefilled syringes.

If you're having trouble locating Lovenox or generic Enoxaparin at your pharmacy, Medfinder can help you search for pharmacies with it in stock near you. You can also ask your doctor about alternative strengths, multi-dose vials, or switching to a different anticoagulant if your specific dose is temporarily unavailable.

With cash prices ranging from $25–$150 for generic and $600+ for brand-name, using discount programs like GoodRx or SingleCare can lead to significant savings if you're paying out of pocket.