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Tamsulosin vs Finasteride: review of effectiveness, side effect.
Drug reviews: use, side effects, effectiveness,  Men's health

Tamsulosin vs Finasteride: use, side effects & effectiveness

Tamsulosin and finasteride are the two most common drugs licensed and used to manage benign prostatic hyperplasia (BPH). BPH is a condition characterised by an enlarged prostate, which may produce common symptoms such as increased urgency to urinate, poor urinary flow (difficult to start urination), increased urination at night (polyuria) and incomplete bladder emptying (individuals going back to the toilet few times because they feel they need to pee). In today’s post, I will review the most common questions surrounding both drugs. Tamsulosin vs finasteride summary of the post:  

  • Tamsulosin vs finasteride: legal classification
  • What tamsulosin and finasteride are used for?
  • What is the difference between tamsulosin and finasteride?
  • Can you take tamsulosin and finasteride at the same time?
  • tamsulosin vs finasteride: side effects  
  • Do finasteride and tamsulosin interact with each other?
  • Which drug is better: tamsulosin or finasteride?
  • Conclusion

Tamsulosin vs finasteride: legal classification

Both drugs are classified as prescription-only medication in the UK, which means a doctor or another qualified prescriber needs to issue a prescription (NHS or private prescription) for supply to happen.

What tamsulosin and finasteride are used for?

Tamsulosin and finasteride are mainly used for the management of benign prostatic hyperplasia (BPH).

At a lower dose, finasteride (1mg) is also used in the treatment of alopecia in male adults (hair loss).

What is BPH (video)?

What is the difference between tamsulosin and finasteride?

Tamsulosin and finasteride belong to a different class of drugs. Tamsulosin is classified as an alpha-blocker, whereas finasteride as 5‑alpha reductase inhibitor. The main difference comes from their mechanism of action.

Tamsulosin mechanism of action (an alpha-blocker)

In simple terms, alpha-blockers, formally known as alpha 1-adrenergic blocking drugsrelax prostatic smooth muscle, which accounts for a large density (amount) of BPH tissues (Lowe, 1999). Relaxation of smooth muscle improves urine flow and reduce lower urinary tract symptoms (Dunn et al., 2002). Tamsulosin starts to work fast and effectively controls moderate to severe symptoms of LUTS and related BPH (ibid).

Finasteride mechanism of action (5‑alpha reductase inhibitor)

5 alpha-reductase is a chemical (enzyme) that converts testosterone to dihydrotestosterone (DHT), both of which are a type of steroids. DHT plays an important role in prostate gland development and growth. Finastessentialps (inhibits) 5 alpha-reductase and therefore reduces the conversion of testosterone to dihydrotestosterone (DHT). This process leads to a reduction in prostate size. It is estimated that the prostate gland shrinks by about 20%, with the corresponding improvement of urinary flow. When the treatment with finasteride is ceased, DHT production increases with symptoms most likely coming back (Steiner, 1996).

The difference in mechanism of action affects how fast initial relief of symptoms is achieved. Read more in the following paragraph: Which drug is better: tamsulosin or finasteride?  

Tamsulosin vs finasteride: which drug is more popular?

Number of prescriptions issued in the last 12 months – Jan—Dec ’20 (, 2021)

  • Finasteride: 3,860,060
  • Tamsulosin: 7,911,361

Tamsulosin is more commonly prescribed in the UK than finasteride. The significant difference in prescribing between tamsulosin and finasteride comes from the main recommendations in the management of lower urinary tract symptoms (LUTS) in men and related conditions, for example, benign prostatic hyperplasia (BPH).

All men with LUTS need to be assessed, including possible referral to a specialist in LUTS management. If ‘conservative’ measures are unsuccessful, drug treatment may be offered. Alpha-blockers (tamsulosin, alfuzosin, doxazosin, or terazosin) are the first-line treatment in males with severe lower urinary tract symptoms.

5‑alpha reductase inhibitor such as finasteride or dutasteride are offered to male patients whose prostate is estimated to be bigger than 30g (weight of the prostate) or a PSA level greater than 1.4 ng/ml.

What is PSA?

Prostate-specific antigen (PSA) is measured (a blood test) to determine prostate size. PSA is produced by the prostate but also by cancer cells in the prostate. Males with a ‘normal’ size prostate have a small amount of PSA in the blood. When the prostate gets bigger, for example, with age, PSA levels increase.  

Can you take tamsulosin and finasteride at the same time?

Tamsulosin and finasteride can be taken at the same time. A combination of an alpha-blocker (tamsulosin) and a 5‑alpha reductase inhibitor (finasteride) is recommended to men with severe LUTS and estimated prostate size bigger than 30g or PSA level greater than 1.4 ng/ml. For the explanation, see the previous paragraph.

Tamsulosin vs finasteride: side effects                      

Both tamsulosin and finasteride are associated with the risk of side effects.

The most common side effects associated with finasteride are:

  • impotence (unable to achieve erection)
  • decreased libido and
  • decreased volume of ejaculate

 Most common side effects which may be experienced by taking tamsulosin:

  • dizziness
  • sexual disfunction (ejaculation disorders, fail to ejaculate)           

Do finasteride and tamsulosin interact with each other?

Both dugs have a distinct mechanism of action. There is no interaction between drugs, and in some way, both drugs complement each other. The treatment with tamsulosin and finasteride aims to decrease urinary tract obstruction symptoms and improve urine flow rate (Steiner, 1996). These effects are achieved with some success by both tamsulosin and finasteride.

Which drug is better: tamsulosin or finasteride?

Few studies compared the effectiveness of tamsulosin and finasteride.

In one study, 403 patients participated in a 52-week trial (Rigatti et al., 2003). Patients were randomly given either tamsulosin or finasteride. This study aimed to compare both drugs’ efficacy and tolerability in patients with lower urinary tract symptoms (BPH).

This study concluded that tamsulosin improved the symptoms to a greater extent than finasteride. Tamsulosin also improved urinary symptoms quicker than tamsulosin.

How long does it take for tamsulosin to work?

The secondary aim of the above study was to measure how quickly symptoms control is achieved. For tamsulosin, about half of the total effect was achieved after one week of the treatment. Maximum improvement in symptoms control for tamsulosin was achieved during week 18 of the study.

Compared to finasteride, tamsulosin worked faster, improving storage symptoms, which are considered most troublesome for patients. After 26 weeks of treatment, both drugs produced the same relieve of symptoms (ibid).

Cochrane Collaboration (a worldwide collaboration of scientists) looked at the effectiveness of finasteride in BPH treatment by looking at different studies (Tacklind et al., 2010). Although comparison of finasteride with alpha-blockers was not the main aim of this study, some valuable facts about finasteride treatment were highlighted in this review.

Finasteride effectively improves urinary symptoms compared to a placebo (a dummy pill) and reduced the risk of BPH progression. Finasteride is less effective than some alpha-blockers (doxazosin and terazosin) but equally effective as tamsulosin.  

Short term use of finasteride does not improve symptoms of BPH, but it does in the long run. Alpha-blocker, doxazosin improves symptoms of BPH better than finasteride in short and long term treatment. The combination of finasteride and doxazosin improves symptom control, both short and long term, with significantly better results than monotherapy with finasteride.

In men with larger prostate, a combination therapy improved symptoms more significantly than single treatment with finasteride.

Combination therapy with two drugs (alpha-blocker and 5‑alpha reductase inhibitor) increases the risk of side effects, including dizziness, asthenia (weakness), erectile and ejaculation disorders and postural hypotension (a drop of blood pressure when an individual stands up).


Finasteride and tamsulosin play an essential role in the management of BPH. The main points to take away are as follows:

  • both finasteride and tamsulosin are effective in the management of BPH
  • tamsulosin provides faster symptom relief than finasteride
  • other alpha-blockers, particularly doxazosin and terazosin, are more effective in symptom control than finasteride.


Dunn CJ, Matheson A, Faulds DM (2002). Tamsulosin: a review of its pharmacology and therapeutic efficacy in the management of lower urinary tract symptoms. Drugs Aging. 2002;19(2):135-61. doi: 10.2165/00002512-200219020-00004. PMID: 11950378. Available at: Accessed on 12/03/2021

Lowe F (1999). Alpha-1-adrenoceptor blockade in the treatment of benign prostatic hyperplasia. Prostate Cancer Prostatic Dis. 1999 May;2(3):110-119. doi: 10.1038/sj.pcan.4500302. PMID: 12496820. Available at: Accessed on 12/03/2021, EBM DataLab, University of Oxford, 2017 Available at: Accessed on 12/03/2021

Rigatti P, Brausi M, Scarpa RM, Porru D, Schumacher H, Rizzi CA; MICTUS Study Group (2003). A comparison of the efficacy and tolerability of tamsulosin and finasteride in patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia. Prostate Cancer Prostatic Dis. 2003;6(4):315-23. doi: 10.1038/sj.pcan.4500680. PMID: 14663474. Available at: Accessed on 14/03/2021

Steiner JF (1996). Clinical pharmacokinetics and pharmacodynamics of finasteride. Clin Pharmacokinet. 1996 Jan;30(1):16-27. doi: 10.2165/00003088-199630010-00002. PMID: 8846625. Available at: Accessed on 13/03/2021

Tacklind J, Fink HA, MacDonald R, Rutks I, Wilt TJ. Finasteride for benign prostatic hyperplasia. Cochrane Database of Systematic Reviews 2010, Issue 10. Art. No.: CD006015. DOI: 10.1002/14651858.CD006015.pub3. Available at: Accessed 14 March 2021.

I am a community pharmacist working in UK. I blog about drugs, health and pharmacy.

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