Does Stinging Nettle Interact With Flomax (Tamsulosin)?

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


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?

Asked by Paul On Aug 29, 2023

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Aug 30, 2023
Last updated Apr 15, 2024

Key points

  • There is no known interaction between Flomax (tamsulosin) and stinging nettle.

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.

Specially, 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!


  • Effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia, PubMed
  • Antiproliferative effect on human prostate cancer cells by a stinging nettle root (Urtica dioica) extract, PubMed
  • [Results of a double-blind study on the effectiveness of ERU (extractum radicis Urticae) capsules in conservative treatment of benign prostatic hyperplasia], PubMed

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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