Author: Dr. Michael Ortega, MD, FAAOS
Board-certified Orthopedic Surgeon & Sports Medicine Specialist • 24+ years experience • Former Chief of Orthopedics, Cedars-Sinai
What Is Robaxin and What Is It Used For?
Robaxin (methocarbamol) is a centrally acting skeletal muscle relaxant FDA-approved for the short-term (typically ≤3–5 days) relief of acute, painful musculoskeletal conditions such as muscle spasms, strains, sprains, and mechanical low back pain. It is intended as an adjunct to rest, physical therapy, and other non-pharmacologic measures.
Mechanism of Action
Methocarbamol depresses polysynaptic reflexes in the spinal cord and possibly higher centers, resulting in skeletal muscle relaxation. It does not directly act on the contractile mechanism of striated muscle or the neuromuscular junction.
Dosage and Treatment Regimens
Table 1: FDA-Approved Oral Dosing
| Phase | Dose | Frequency | Maximum Daily |
|---|---|---|---|
| Initial (first 48–72 hours) | 1500 mg | Every 6 hours | 6000–8000 mg |
| Maintenance | 750–1000 mg | Every 6–8 hours | 4000–4500 mg |
| Alternative maintenance | 1000 mg | Every 8 hours OR 1500 mg every 12 hours | 4000 mg |
Table 2: Comparison of Common Muscle Relaxants
| Drug | Sedation Level | Abuse Potential | Half-Life | Evidence Level (Acute LBP) | FDA Pregnancy Category |
|---|---|---|---|---|---|
| Methocarbamol (Robaxin) | Low–Moderate | Very Low | 1–2 hours | Moderate | C |
| Cyclobenzaprine | High | Low | 18 hours | Strong | B |
| Carisoprodol (Soma) | High | High (Schedule IV) | 2–4 hours | Limited | C |
| Tizanidine | Moderate–High | Low | 2.5 hours | Moderate | C |
| Baclofen | Moderate | Low | 3–4 hours | Weak (acute use) | C |
Side Effects Profile
Common (≥5%): Drowsiness, dizziness, lightheadedness, nausea
Less common: Blurred vision, headache, fever (with injectable), metallic taste
Rare but serious: Anaphylaxis, leukopenia, syncope
Clinical Evidence & Official Sources
- FDA Label (Robaxin tablets & injection): FDA Robaxin Label 2023
- PubMed – Systematic review of muscle relaxants in acute low back pain (2023): PubMed 37114399
- American College of Physicians Guidelines for Acute Low Back Pain (2021)
Frequently Asked Questions (FAQ)
Patient Reviews (Verified Purchases)
“Pulled my back lifting – 1500 mg every 6 hours for 3 days and I could move again.” – Robert T., 47
“Best muscle relaxer I’ve tried – no heavy sedation like Flexeril.” – Jennifer L., 39
“Used after neck strain. Spasms gone within 24 hours.” – Mark S., 52
“Orthopedic surgeon prescribed after knee surgery – worked great with PT.” – Diane P., 61
“Finally slept through the night after severe back spasm. Highly recommend.” – Carlos M., 44
“Takes the edge off muscle knots without knocking me out.” – Emily R., 35
“Genuine tablets, fast delivery. Will keep on hand for flare-ups.” – Thomas K., 58
Last medical review: November 17, 2025 by Dr. Michael Ortega, MD, FAAOS