What the FDA labels say about taking them together
Methylene blue and venlafaxine
Venlafaxine's FDA label of August 15, 2023 names methylene blue in its contraindications section; methylene blue's label does not name venlafaxine itself but warns about its class (SNRIs (serotonin and norepinephrine reuptake inhibitors)). The venlafaxine label: “• taking, or within 14 days of stopping, MAOIs because of the risk of serotonin syndrome.”
Check it at the source: the methylene blue FDA label on DailyMed (effective May 28, 2025, American Regent, Inc.); the venlafaxine FDA label on DailyMed (effective August 15, 2023, Viatris Specialty LLC).
What does the methylene blue label say about venlafaxine?
Methylene blue's label does not name venlafaxine itself; it warns about its class (SNRIs (serotonin and norepinephrine reuptake inhibitors)):
Methylene blue label, drug interactionsAvoid concomitant use of PROVAYBLUE with medicinal products that enhance serotonergic transmission including antidepressants like SSRIs (selective serotonin reuptake inhibitors), SNRIs (serotonin and norepinephrine reuptake inhibitors), MAOIs (monoamine oxidase inhibitors), bupropion, buspirone, clomipramine, mirtazapine, linezolid, opioids, and dextromethorphan because of the potential for serious CNS reactions, including potentially fatal serotonin syndrome.
Methylene blue label, boxed warningAvoid concomitant use of PROVAYBLUE with selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs) and opioids. [see Warnings and Precautions ( 5.1 ) and Drug Interactions ( 7.1 )].
Source: FDA drug label (PROVAYBLUE), NDA204630 (Provepharm Sas), as published by American Regent, Inc., effective May 28, 2025 (SPL set 4f6848e5-35ed-4046-b13c-3032b5ba3232), via openFDA; the full label on DailyMed
What does the venlafaxine label say about methylene blue?
Venlafaxine label, contraindications• taking, or within 14 days of stopping, MAOIs (including the MAOIs linezolid and intravenous methylene blue) because of the risk of serotonin syndrome [see Dosage and Administration (2.11), Warnings and Precautions (5.2), and Drug Interactions (7.1) ].
Venlafaxine label, drug interactionsIntervention; Concomitant use of Effexor XR is contraindicated in patients taking MAOIs, including MAOIs such as linezolid or intravenous methylene blue [see, and ].
Venlafaxine label, warnings and precautionsIf it is necessary to initiate treatment with an MAOI such as linezolid or intravenous methylene blue in a patient taking Effexor XR, discontinue Effexor XR before initiating treatment with the MAOI [see Contraindications (4), Drug Interactions (7.1) ].
Venlafaxine label (Almatica Pharma LLC, October 9, 2025), contraindicationsCONTRAINDICATIONS Venlafaxine Extended-Release Tablets are contraindicated in patients: with known hypersensitivity to venlafaxine besylate, venlafaxine hydrochloride, desvenlafaxine succinate or to any excipients in Venlafaxine Extended-Release Tablets [see Adverse Reactions ( 6.2 )]. taking, or within 14 days of stopping, MAOIs (including the MAOIs linezolid and intravenous methylene blue) because of increased risk of serotonin syndrome [see Dosage and Administration ( 2.9 ), Warnings and Precautions ( 5.2 ), Drug Interactions ( 7.1 )].
Venlafaxine label (Almatica Pharma LLC, October 9, 2025), drug interactionsIntervention; Concomitant use of Venlafaxine Extended-Release Tablets is contraindicated in patients taking MAOIs, including MAOIs such as linezolid or intravenous methylene blue [see Dosage and Administration (), Contraindications (), and Warnings and Precautions ()].
Venlafaxine label (Almatica Pharma LLC, October 9, 2025), warnings and precautionsIf it is necessary to initiate treatment with an MAOI such as linezolid or intravenous methylene blue in a patient taking Venlafaxine Extended-Release Tablets, discontinue Venlafaxine Extended-Release Tablets before initiating treatment with the MAOI [see Dosage and Administration ( 2.9 ), Contraindications ( 4 ), Drug Interactions ( 7.1 )].
Source: FDA drug label (Venlafaxine, NDA215429), Almatica Pharma LLC, effective October 9, 2025 (SPL set e81a2daf-b8b2-7c05-b532-bc775700b100), via openFDA
Source: FDA drug label (Effexor XR), NDA020699 (Upjohn), as published by Viatris Specialty LLC, effective August 15, 2023 (SPL set c848a5d8-ba94-4c84-80e3-0bf35fb8e32e), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Methylene blue | Venlafaxine | |
|---|---|---|
| Labeled for | n/a | Depression, Anxiety |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | $0.0799 per capsule 75 mg capsule |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once