Milnacipran (Savella) Side Effects: What to Expect and When to Call Your Doctor

Starting a new medication for fibromyalgia can feel like a balancing act. You want pain relief — but you don't want to trade one set of problems for another. Understanding what side effects to expect from Milnacipran (Savella), which ones are normal to push through, and which are red flags requiring medical attention can make a big difference in your experience on this medication.

What Is Milnacipran's Black Box Warning?

Like all SNRIs and antidepressants, Milnacipran carries a black box warning — the FDA's most serious warning level — about the risk of suicidal thoughts and behavior in children, adolescents, and young adults (under age 24). This risk is highest during the first few months of treatment and when the dose is changed.

Important context: Milnacipran is not FDA-approved for depression in the US. However, it belongs to the same drug class, and the black box warning applies. If you or a family member are under 24 or have a history of depression, discuss this risk carefully with your prescriber before starting.

Common Side Effects (Experienced by 5% or More of Patients)

These are the side effects most frequently reported in clinical trials. Many occur most prominently in the first few weeks and may improve with time:

Nausea. The most common complaint. Often worst in the first 1-2 weeks. Taking Milnacipran with food can significantly reduce nausea. It typically improves as your body adjusts.

Headache. Often present during titration; usually subsides.

Constipation. Increase water and fiber intake. OTC remedies like Miralax are generally safe to use — confirm with your pharmacist.

Dizziness. More common at higher doses or during dose increases. Rise slowly from sitting or lying positions.

Insomnia. Taking the evening dose 6+ hours before bedtime may help. Discuss persistent sleep problems with your prescriber.

Hot flushes and excessive sweating (hyperhidrosis). A class effect of SNRIs. These may not diminish with continued use. If intolerable, discuss with your doctor.

Heart rate increase (tachycardia). Your provider will monitor your heart rate during treatment. A mild increase is expected; a significantly elevated or sustained increase needs medical attention.

Palpitations. Awareness of your heartbeat, sometimes fluttering. Usually mild; report if persistent or alarming.

Dry mouth. Sip water throughout the day and avoid sugary drinks that can worsen dental issues from dry mouth.

Elevated blood pressure. Monitor your blood pressure regularly when starting Milnacipran, especially if you already have hypertension.

Serious Side Effects: Call Your Doctor Right Away

These are less common but require prompt medical attention:

Serotonin syndrome. Signs include rapid heart rate, high blood pressure, high fever, muscle twitching, agitation, confusion, or loss of coordination. This is a medical emergency. Call 911 immediately.

Liver damage. Symptoms include yellowing of the skin or eyes (jaundice), dark urine, severe abdominal pain, and unusual fatigue. Cases of severe liver injury including fulminant hepatitis have been reported with milnacipran from postmarketing experience.

Seizures. Some patients have reported seizures while taking milnacipran. Stop the medication and contact your provider immediately if you experience muscle twitching, jerking, or uncontrolled movements.

Hyponatremia (low sodium). Symptoms include headache, confusion, hallucinations, weakness, or unsteadiness. Risk is higher in elderly patients and those on diuretics.

Urinary retention. More common in male patients, especially those with prostate enlargement. Difficulty urinating or inability to empty the bladder completely requires medical evaluation.

Manic episodes. Milnacipran may activate mania or hypomania in patients with mood disorders. Signs include unusually elevated or irritable mood, decreased need for sleep, rapid speech, or impulsive behavior.

Abnormal bleeding. Milnacipran may increase bleeding risk, especially when combined with NSAIDs, aspirin, or blood thinners. Report unusual bruising or bleeding to your provider.

Side Effects Specific to Male Patients

Male patients taking Milnacipran may experience ejaculatory delay or failure, decreased libido, and erectile dysfunction — effects common to SNRI medications. Additionally, testicular pain has been reported specifically with milnacipran. Men with existing prostate hypertrophy or prostatitis face elevated risk of urinary retention and should be monitored closely.

Tips for Managing Common Side Effects

Nausea: Always take with food; eat small, frequent meals; ginger tea or ginger chews may help

Insomnia: Take evening dose 6+ hours before bedtime; avoid caffeine after noon; consider a short-term sleep aid with doctor approval

Elevated BP: Monitor at home with a home cuff; reduce sodium, alcohol, and caffeine; report sustained elevations

Dry mouth: Sip water frequently; use sugar-free gum or lozenges; see your dentist regularly

For information on drug interactions that can worsen these risks, see our post on Milnacipran drug interactions. And if you're having trouble finding Milnacipran at your pharmacy, medfinder can help you locate it near you.