Does Stinging Nettle Interact With Flomax (Tamsulosin)?

In our latest question and answer, the pharmacist discusses the potential interaction between stinging nettle and Flomax.

3 min read Updated Jun 2026 2,849 views
Does Stinging Nettle Interact With Flomax (Tamsulosin)?
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Paul asked

Hi, I'm a 69-year-old male with an enlarged prostate. I have just started taking Flomax (Tamsulosin HCl) 4 mg capsules. They have achieved the intended results, as I can urinate a bit more comfortably. I'm not particularly fond of taking them and I'm skeptical about potential long-term effects they might carry. I'm interested in experimenting with stinging nettle root to observe its effects on me. My question is, do you think it's safe to use tamsulosin and stinging nettle root concurrently, or should it be a choice between the two?

Aug 29, 2023
The quick answer
  • Stinging nettle root has no known interactions with tamsulosin and appears safe to take together. Tamsulosin works by relaxing muscles in the prostate while stinging nettle may work through different mechanisms, and they do not share similar side effects. It is important to consult with your healthcare professional before starting stinging nettle or any new supplement.
A quick summary of Dr. Brian Staiger, PharmD's full answer below, condensed by AI from that answer only (not from any outside source). The pharmacist's answer is the source of record.
Medications in this answer — tap to explore

Quick Answer

Stinging nettle root is not known to interact with tamsulosin (brand name Flomax), and they appear safe to take together. However, it's always essential to consult with a healthcare professional before starting any new supplement or medication so you can be appropriately monitored.

Detailed Answer

Stinging nettle, scientifically known as Urtica dioica, is a plant native to Europe, Asia, North America, and North Africa. It has been utilized in herbal medicine for centuries. One of its applications includes the treatment of symptoms related to benign prostatic hyperplasia (BPH), a condition that you're likely dealing with, given your description.

Stinging nettle is believed to offer potential benefits to the prostate through various mechanisms. These mechanisms include:

  • Stinging nettle contains a compound called beta-sitosterol, which laboratory studies have shown to possess antiproliferative effects on the prostate. This suggests that it could inhibit growth factors contributing to an enlarged prostate.

  • The components of stinging nettle root have demonstrated inhibitory effects on an enzyme known as aromatase. Aromatase is responsible for converting androgens into estrogens. Given that estrogens are thought to be involved in BPH, inhibiting aromatase could potentially alleviate BPH symptoms.

  • Preliminary research indicates that stinging nettle root extract may hinder the sodium-potassium pump in hyperplastic prostate tissue. This action could lead to a reduction in prostate cell metabolism and growth.

Flomax works differently than stinging nettle. It is a medication that relaxes the muscles in the prostate and bladder neck, facilitating easier urination.

Specifically, Flomax is a selective antagonist of alpha-1 adrenergic receptors, particularly the alpha-1A subtype. It binds to these receptors, which are found on the smooth muscle cells of the prostate, bladder neck, and urethra. As a result of this binding, the muscle tone in these areas decreases, allowing urine to pass more freely through the urethra and relieving urinary symptoms associated with BPH.

Regarding your specific inquiry, there isn't evidence to suggest an interaction between stinging nettle root and Flomax (tamsulosin).

Beyond the interaction of one drug or supplement with another, it's crucial to consider the possibility of shared or additive side effects when combining medications. Fortunately, Flomax and stinging nettle do not appear to have many common side effects.

Flomax is associated with a distinct set of primary side effects, which may include:

  • Dizziness
  • Headache
  • Runny or stuffy nose
  • Potential decrease in blood pressure

In contrast, stinging nettle is generally reported to be well tolerated in most individuals.

Overall, it seems that Flomax and stinging nettle do not interfere with each other's efficacy or absorption in the body, and they do not seem to share similar side effects. Although studies specifically evaluating this combination are lacking, it appears to be safe to take them together.

Final Words

Always bear in mind that while natural supplements like stinging nettle can complement standard treatments, they should not serve as replacements for these treatments unless recommended by a healthcare professional.

Thank you for reaching out, and I hope this information proves helpful!

References & sources
  1. Effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia — PubMed
  2. Antiproliferative effect on human prostate cancer cells by a stinging nettle root (Urtica dioica) extract — PubMed
  3. [Results of a double-blind study on the effectiveness of ERU (extractum radicis Urticae) capsules in conservative treatment of benign prostatic hyperplasia] — PubMed
Glossary — Terms in This Answer
Benign prostatic hyperplasia (BPH)
A condition where the prostate gland becomes enlarged and causes difficulty with urination.
Beta-sitosterol
A plant compound found in stinging nettle that may help slow the growth of prostate cells.
Antiproliferative effects
The ability to slow down or stop the growth and multiplication of cells.
Aromatase
An enzyme in the body that converts male hormones (androgens) into female hormones (estrogens).
Androgens
Male hormones such as testosterone.
Sodium-potassium pump
A mechanism in cells that helps maintain balance of certain minerals and controls cell activity.
Alpha-1 adrenergic receptors
Protein sites on muscle cells in the prostate and bladder that control muscle tightness.
Antagonist
A substance that blocks or reduces the effect of another substance in the body.
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Dr. Brian Staiger, PharmD
About the pharmacist

Dr. Brian Staiger, PharmD

Clinical Pharmacy

Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified

Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...

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