Comprehensive medication guide to Phenergan including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$15 copay for generic promethazine; covered as Tier 1 (preferred generic) on most Medicare Part D and commercial insurance plans. Prior authorization is rarely required for tablets.
Estimated Cash Pricing
$15–$30 retail for generic promethazine tablets (30 count, 25 mg); as low as $5.83 with a GoodRx coupon. Suppositories cost $100+ retail but drop to ~$26 with coupons. Oral solution ranges $10–$40.
Medfinder Findability Score
42/100
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Phenergan is the brand name for promethazine hydrochloride, a first-generation antihistamine and phenothiazine drug that has been available in the United States since 1951. While the original Phenergan brand has been discontinued, generic promethazine remains widely prescribed — with over 1 million prescriptions written in the US in 2023 alone.
Promethazine is FDA-approved to treat nausea and vomiting (including post-operative nausea, motion sickness, and pregnancy-related nausea), allergic conditions (hay fever, allergic rhinitis, hives, allergic reactions), and for pre- and post-operative sedation. It is also used as an adjunct to analgesics for pain management in surgical settings.
Promethazine is available as oral tablets (12.5 mg, 25 mg, 50 mg), oral solution/syrup (6.25 mg/5 mL), rectal suppositories (12.5 mg, 25 mg), and injectable form (25 mg/mL and 50 mg/mL, for clinical use only). It is not a controlled substance, so any licensed prescriber can write a prescription and telehealth providers can prescribe it without DEA schedule restrictions.
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Promethazine works through a multi-receptor mechanism. It blocks H1 histamine receptors throughout the body — both peripherally (in skin, nasal passages, and airways) and centrally (in the brain). Peripheral H1 blockade reduces allergy symptoms like itching, runny nose, and sneezing. Central H1 blockade suppresses the arousal system, causing sedation, and dampens vestibular signals that trigger motion sickness.
For nausea control, promethazine also blocks dopamine D2 receptors in the chemoreceptor trigger zone (CTZ) — a brain area that detects toxins and triggers vomiting. By blocking these receptors, promethazine prevents the nausea signal from being transmitted. Additionally, promethazine blocks muscarinic acetylcholine receptors (anticholinergic activity), which contributes to dry mouth, constipation, blurred vision, and urinary retention as side effects.
Onset of effect is typically 20–30 minutes for oral and rectal formulations, with peak effects in 1–2 hours. Effects last approximately 4–8 hours per dose. The drug's half-life is 10–19 hours, so cumulative sedation can occur with repeated dosing.
12.5 mg — tablet
Lowest oral tablet dose; used for mild symptoms or in children 2+
25 mg — tablet
Most commonly prescribed strength for nausea, motion sickness, and allergies
50 mg — tablet
Used for pre-operative sedation and severe symptoms
6.25 mg/5 mL — oral solution
Liquid form for patients who cannot swallow tablets
12.5 mg — rectal suppository
Lower-dose suppository; good when vomiting prevents oral use
25 mg — rectal suppository
Standard suppository dose; available as Promethegan or generic
25 mg/mL — injection (IM only)
Clinical setting only; IV administration strongly contraindicated
50 mg/mL — injection (IM only)
Higher concentration injectable; clinical setting only
Finding promethazine in 2026 is genuinely challenging. The injectable form is in active shortage — Hikma has multiple presentations on back order with an estimated release date of early January 2027. Oral tablets, suppositories, and oral solution have been flagged as supply concerns since October 2025, with stock described as available but limited and highly variable by pharmacy and region.
Availability varies significantly even between pharmacies in the same city. Some patients are able to fill their prescription with minimal difficulty, while others report checking five or more pharmacies without success. Independent pharmacies and hospital outpatient pharmacies sometimes have stock when major chains do not.
Rather than calling pharmacies one by one, use medfinder to search for promethazine in stock near you. medfinder contacts pharmacies in your area and texts you which ones can fill your prescription, saving you hours of frustrating hold times.
Because promethazine is not a DEA-scheduled controlled substance, any licensed prescriber with standard prescribing authority can write a promethazine prescription. No special DEA registration or additional licensing is required beyond a standard prescriber license.
Primary care physicians (PCPs) and internal medicine physicians
Emergency medicine physicians
OB-GYNs and obstetricians (commonly for pregnancy nausea)
Allergists and immunologists
Anesthesiologists and CRNAs (for perioperative use)
Nurse practitioners (NPs) and physician assistants (PAs) — most states grant full prescribing authority for non-controlled substances
Telehealth options: Because promethazine is not a controlled substance, it can be prescribed via telehealth platforms (Teladoc, MDLive, Amwell, QuickMD, your insurance's telehealth benefit) through a video or phone visit. This makes it easy to get a prescription quickly without an in-person visit. Urgent care clinics are another fast option for patients who need a prescription the same day.
No. Promethazine (Phenergan) is not a controlled substance under the DEA Controlled Substances Act and has no DEA schedule. This means any licensed prescriber with standard prescribing authority can write a promethazine prescription — no special DEA registration or Schedule II prescription form is required.
Telehealth providers can prescribe promethazine without the restrictions that apply to scheduled medications. Prescriptions can be called into the pharmacy rather than requiring a written prescription. There are no mandated refill restrictions based on scheduling, though prescribers may still limit refills based on clinical judgment.
Note: Some promethazine combination products (like promethazine with codeine) are controlled substances because of the codeine component. However, plain promethazine alone is not scheduled.
Drowsiness and sedation (most common)
Dizziness
Confusion or disorientation
Dry mouth
Blurred vision
Constipation
Nasal congestion
Extrapyramidal symptoms: tremors, muscle stiffness, restlessness (akathisia), dystonia
Tardive dyskinesia (with long-term use)
Respiratory depression (especially in children under 2 — Black Box Warning — and with CNS depressants)
Neuroleptic Malignant Syndrome (NMS): high fever, severe muscle stiffness, sweating, rapid heartbeat, confusion
Severe tissue injury/gangrene with IV administration — IV route not recommended (Black Box Warning)
Cardiac arrhythmias and QT prolongation
Seizures (especially in patients with seizure disorders)
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Ondansetron (Zofran)
5-HT3 serotonin antagonist; widely available; less sedating than promethazine; effective for post-op, chemo, and general nausea; available as tablet, ODT, and liquid
Metoclopramide (Reglan)
Dopamine antagonist with prokinetic activity; useful when gastroparesis contributes to nausea; boxed warning for tardive dyskinesia with use over 12 weeks
Meclizine (Bonine)
OTC antihistamine; excellent for motion sickness and vertigo; less sedating than promethazine; no prescription needed
Prochlorperazine (Compazine)
Same phenothiazine class; similar antiemetic mechanism; less sedating; also experiencing supply disruptions in 2026
Prefer Phenergan? We can find it.
Opioids (oxycodone, hydrocodone, morphine, codeine)
majorProfound CNS depression, respiratory depression, coma, and death possible. Use only when no alternative exists; minimize doses; monitor closely.
Benzodiazepines (diazepam, lorazepam, alprazolam)
majorAdditive CNS depression; increased risk of over-sedation, respiratory depression, and falls.
Alcohol
majorDramatically increases sedation and impairs coordination. Avoid entirely during promethazine therapy.
MAO inhibitors (phenelzine, tranylcypromine, isocarboxazid)
majorIntensified anticholinergic and CNS depressant effects. Allow 14-day washout after MAOI before starting promethazine.
Sodium oxybate (GHB/Xyrem)
majorContraindicated combination. Profound sedation and respiratory depression.
Levodopa and dopaminergic drugs
majorPromethazine antagonizes dopamine receptor activity, worsening Parkinson's symptoms.
QT-prolonging agents (amiodarone, antipsychotics, certain antibiotics)
majorAdditive QT prolongation and risk of arrhythmias. Monitor ECG when combination is necessary.
Anticholinergic medications (tricyclics, scopolamine, oxybutynin)
moderateAdditive anticholinergic burden: dry mouth, constipation, urinary retention, confusion especially in elderly.
CYP2D6 inhibitors (fluoxetine, paroxetine, desvenlafaxine)
moderateIncreased promethazine blood levels possible due to reduced metabolism. May intensify side effects.
Diphenhydramine (Benadryl)
moderateAdditive anticholinergic and sedative effects. Avoid combining two first-generation antihistamines.
Promethazine has been a cornerstone antiemetic and antihistamine since 1951, valued for its broad activity across nausea, allergies, motion sickness, and sedation. Its multi-receptor mechanism makes it more versatile than single-pathway drugs, though this same breadth also produces its notable side effect profile — especially sedation and anticholinergic effects. For most healthy adults using it short-term, promethazine remains safe and effective when used as directed.
In 2026, the primary challenge for patients is not cost but availability. Generic promethazine is extremely affordable — as low as $5.83 with a GoodRx coupon for tablets — but supply disruptions mean your local pharmacy may not have it in stock. Checking multiple pharmacies, considering alternative formulations (suppositories if tablets are unavailable), and asking your provider about therapeutic alternatives (ondansetron, metoclopramide, meclizine) are key strategies.
If you're struggling to find promethazine in stock near you, medfinder can help. medfinder contacts pharmacies in your area and texts you which ones can fill your specific promethazine prescription — no hold times, no repeated calls.
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