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Not medical advice. The Atlas is not a substitute for a clinician who can examine you.

Stinging Nettle Root

Urtica dioica Root (the SHBG / free-testosterone claim)

Evidence grade 2 of 5, Thin. Read how the Atlas grades evidence.

The written rationale for this grade is still being prepared.

FDA
Not FDA-approved; dietary supplement

Reference only. Not medical advice.

What can go wrong

Generally well tolerated; mild GI upset and, occasionally, allergic reactions. As with other prostate botanicals, it can affect urinary and prostate evaluation and should be disclosed to clinicians. Drug interactions (e.g., with diabetes or blood-pressure medication) are theoretically possible.

This is something to take to a clinician. The Atlas can tell you what is known about stinging nettle root in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.

Stinging nettle root is included in testosterone blends on the theory that its lignans bind sex hormone-binding globulin (SHBG), displacing testosterone and raising free testosterone. This binding is shown mostly in vitro; controlled human evidence that nettle meaningfully raises free testosterone is lacking. Its better-studied use is for BPH urinary symptoms, often combined with saw palmetto.

A popular 'frees up testosterone by blocking SHBG' theory with mostly in-vitro support.

What people take it for

These are the reasons people give for taking it. They are not effects it has been shown to have.

  • Marketed to raise free testosterone
  • BPH lower urinary tract symptoms
  • Anti-inflammatory / allergy folk use

How it is supposed to work

Nettle-root lignans and beta-sitosterol bind SHBG in laboratory assays, which in theory would reduce SHBG-bound testosterone and increase the free, bioavailable fraction. It is also proposed to weakly inhibit aromatase and 5-alpha-reductase. Whether any of this changes circulating free testosterone in humans at supplement doses is unproven.

In vitro is not in vivo

A compound binding SHBG in a test tube does not establish that an oral dose reaches concentrations sufficient to shift free testosterone in the body. The leap from SHBG-binding assays to 'raises your free T' is the central unverified step in the marketing.

What people get wrong

  • Often saidNettle root raises free testosterone

    ActuallySHBG binding is shown mainly in vitro; there is no convincing human evidence that oral nettle meaningfully increases free testosterone.

  • Often saidIt is interchangeable with saw palmetto

    ActuallyThey have distinct proposed mechanisms; nettle's stronger evidence is for urinary symptoms, not hormones.

Who profits, and who pushes back

Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.

What we do not know

  • Does any oral dose achieve plasma levels that shift SHBG binding in vivo?
  • Is the BPH benefit independent of co-administered saw palmetto?

At a glance

Proposed action
Lignans bind SHBG (in vitro)
Claimed result
More free testosterone
Human T evidence
Lacking / unconvincing
Better-studied use
BPH urinary symptoms

What this entry does not yet cover

What follows is unfinished work on our side, not a finding about Stinging Nettle Root. A short entry is not a safe entry.

  • Timeline. We have not built the dated record of research and regulatory events.
  • Cost and market. We have not documented what it sells for or who sells it.
  • Supply chain. We have not mapped where it is made.
  • Who uses it. We have not documented the user groups.
  • What could change. No forward-looking summary yet.
  • How it compares. We have not set it against the alternatives.
  • Children and teenagers. We have not checked what is known about younger people.

Sources

The studies below are named and described, but not linked. You cannot open them from here and check our reading against them, which means this page is our summary of the literature rather than a document you can verify. Weigh it accordingly until the links exist.

The studies that matter

  • Schottner et al. (SHBG-binding lignans, in vitro)1997

    Nettle-root lignans bound SHBG in laboratory assays

  • Safarinejad (nettle for BPH, RCT)2005

    Improved lower urinary tract symptoms vs placebo; not a testosterone endpoint