Comprehensive medication guide to Flomax 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 tamsulosin on most commercial insurance plans; typically Tier 1–2 on Medicare Part D plans; prior authorization rarely required but possible on some plans.
Estimated Cash Pricing
$50–$108 retail for a 30-day supply of generic tamsulosin 0.4 mg; as low as $4.38 with a GoodRx coupon or $9.39 for a 90-day supply at discount pharmacies.
Medfinder Findability Score
82/100
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Flomax is the brand name for tamsulosin hydrochloride, an FDA-approved medication used to treat the urinary symptoms of benign prostatic hyperplasia (BPH), also known as an enlarged prostate. It was first approved by the FDA in 1997 and belongs to the drug class known as alpha-1 adrenergic receptor blockers (alpha blockers). The brand-name Flomax has been discontinued in the United States; all prescriptions are now filled with generic tamsulosin, which is bioequivalent and therapeutically identical.
Tamsulosin is one of the most commonly prescribed medications in the United States, with over 22 million prescriptions dispensed in 2023 alone — making it the 24th most-prescribed drug in the country. It is available in 0.4 mg oral capsules and is typically taken once daily, 30 minutes after the same meal each day.
In addition to its FDA-approved BPH indication, tamsulosin is frequently used off-label to help facilitate the passage of ureteral kidney stones between 4–10 mm in diameter. It works by relaxing the smooth muscle in the ureter, widening the passage for stone passage.
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Tamsulosin selectively blocks alpha-1A and alpha-1D adrenergic receptors located in the prostate, bladder neck, and urethra. When these receptors are blocked, the smooth muscle in these areas relaxes, reducing the muscular obstruction to urine flow. This is why tamsulosin can relieve BPH symptoms within days without shrinking the prostate itself.
Because tamsulosin is highly selective for alpha-1A and alpha-1D receptors (which are concentrated in urinary tract tissue rather than blood vessels), it has significantly less effect on blood pressure than older, non-selective alpha blockers like doxazosin and terazosin. This makes tamsulosin better tolerated — with less dizziness and hypotension — while still providing effective urological symptom relief.
Tamsulosin is extensively metabolized in the liver by enzymes CYP3A4 and CYP2D6. This is why it has important drug interactions with CYP3A4 inhibitors (like ketoconazole) and CYP2D6 inhibitors (like paroxetine), which can raise tamsulosin blood levels to potentially dangerous levels.
0.4 mg — capsule
Standard starting dose. Take once daily, 30 minutes after the same meal each day. Do not crush or open capsule.
0.8 mg — capsule
Maximum dose. Only used if 0.4 mg is inadequate after 2-4 weeks. Achieved by taking two 0.4 mg capsules.
Tamsulosin is generally widely available across the United States. As of 2026, it is not listed on the FDA Drug Shortages Database. With over 22 million annual prescriptions and manufacturing by multiple FDA-approved generic producers, the nationwide supply is stable.
However, individual pharmacies — especially smaller independent locations — can occasionally run low on stock due to high local demand, wholesaler delays, or formulary-driven patient migrations. If your usual pharmacy is out, the best strategy is to check multiple nearby locations. Large chain pharmacies (Walmart, CVS, Walgreens, Costco) tend to stock higher volumes of common generics like tamsulosin and are less likely to run out.
If you need help finding tamsulosin near you, medfinder calls pharmacies in your area to check which ones have your medication in stock, then texts you the results — no hold music, no repeated calls.
Tamsulosin is not a controlled substance and has no DEA scheduling. It can be prescribed by any licensed healthcare provider in the United States without special registration or controlled substance prescribing authority.
Urologists (the primary specialists for BPH management)
Primary care physicians (family medicine, internal medicine)
Geriatricians
Nurse practitioners (NPs) and physician assistants (PAs)
Nephrologists (for kidney stone-related prescribing)
Tamsulosin is available via telehealth. Multiple platforms including Hims, Ro, Teladoc, and MDLive can evaluate BPH symptoms online and send a tamsulosin prescription directly to a patient's pharmacy of choice, making it one of the more accessible prescription medications for remote prescribing.
No. Tamsulosin (Flomax) is not a controlled substance and has no DEA schedule. It can be prescribed by any licensed healthcare provider — including primary care physicians, urologists, nurse practitioners, and physician assistants — without any special DEA registration or documentation requirements.
Tamsulosin prescriptions can be refilled at standard intervals without restrictions. Prescription transfers between pharmacies are permitted without limitation. The medication can also be prescribed via telehealth platforms, since it does not require in-person prescribing requirements that apply to controlled substances.
Dizziness and lightheadedness (especially after first dose)
Orthostatic hypotension (blood pressure drop on standing)
Retrograde ejaculation (semen entering bladder during orgasm)
Headache
Rhinitis (runny or stuffy nose)
Fatigue and weakness
Insomnia
Priapism (prolonged painful erection — rare, <1 in 50,000 patients; medical emergency)
Severe allergic reaction including angioedema, urticaria, and skin rash
Intraoperative Floppy Iris Syndrome (IFIS) — important warning for patients undergoing cataract or glaucoma surgery
Syncope (fainting) from severe hypotension — especially with first dose or in elderly patients
Stevens-Johnson syndrome (extremely rare, severe skin reaction)
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Silodosin (Rapaflo)
Most selective alpha-1A blocker; less blood pressure effect, but higher retrograde ejaculation rate (~22%). Good for cardiovascular-sensitive patients.
Alfuzosin (Uroxatral)
Uroselective alpha blocker with the lowest ejaculatory side effect rate; preferred for sexually active patients. No dose titration required.
Doxazosin (Cardura)
Non-selective alpha blocker for BPH and hypertension. Requires dose titration. More hypotension risk but very inexpensive.
Finasteride (Proscar)
5-alpha reductase inhibitor that shrinks prostate tissue over 3-6 months. Different mechanism from tamsulosin; often combined for large prostates.
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Sildenafil (Viagra), Tadalafil (Cialis), Vardenafil (Levitra)
majorAdditive vasodilation can cause dangerous hypotension. Combination only under provider supervision at minimum effective doses.
Ketoconazole and strong CYP3A4 inhibitors
majorContraindicated. Increases tamsulosin Cmax 2.2× and AUC 2.8×. Avoid combination.
Alfuzosin, doxazosin, terazosin, silodosin (other alpha blockers)
majorAdditive hypotension risk. Do not combine alpha blockers.
Paroxetine (Paxil) and strong CYP2D6 inhibitors
moderateIncreases tamsulosin levels. Monitor for increased side effects including hypotension and dizziness.
Cimetidine (Tagamet)
moderateReduces tamsulosin clearance by 26%; increases AUC by 44%. Use with caution; monitor for increased side effects.
Warfarin
moderateInconclusive interaction data. Use with caution and maintain regular INR monitoring.
Grapefruit juice
minorCYP3A4 inhibition may increase tamsulosin absorption. Limit consumption if experiencing increased dizziness.
Flomax (tamsulosin) is a highly effective, well-established, and remarkably affordable medication for benign prostatic hyperplasia. It has been on the market since 1997, is manufactured by multiple generic producers, and is covered by most insurance plans at minimal copay. For uninsured patients, GoodRx coupons can reduce the cost to under $5 per month.
While there is no national shortage of tamsulosin in 2026, occasional local stock-outs can frustrate patients. The best strategy is to refill prescriptions early, consider a 90-day mail-order supply, and use tools designed to check pharmacy availability. Key drug interactions — especially with PDE5 inhibitors and strong CYP3A4 inhibitors — should be reviewed with every prescribing encounter.
If you're having trouble locating tamsulosin at your pharmacy, medfinder calls pharmacies near you to find which ones have it in stock and texts you the results — saving you the time of calling every location yourself.
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Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
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