Educational information, not medical advice.See how evidence is graded

Suo Yang

Traditionally used for: People working with a qualified TCM practitioner who want a traditional kidney-yang tonic.

Home

What is Suo Yang? Suo Yang is the dried, fleshy stem of a desert plant, Cynomorium songaricum. It is also called Cynomorium stem. It is used as a single herb in Traditional Chinese Medicine (TCM). In tradition it is given to people said to have "kidney yang deficiency". That is a TCM pattern of feeling cold, tired and weak in the lower back and knees, with low sex drive. It is also given to soften dry, hard stools in older or frail people. Here is the evidence verdict up front. Almost all research on Suo Yang is lab and animal work. We could not find published human trials that test it on its own for any of its traditional uses, so its effects in people are unproven. Long use and scientific proof are two different things. Suo Yang has a long, well-recorded place in Chinese herbal medicine, but that history does not show that it works. This page reports both points separately. You will not see that caution repeated in every section below. How does Suo Yang work? Nobody has shown how Suo Yang works in people. The honest answer is that we do not know. In TCM theory it is said to "warm and boost kidney yang", feed essence and blood, and moisten the gut. These are traditional ideas about body patterns. They are not things we can measure in a lab. Lab and animal studies point in a few directions. Extracts show antioxidant action, which means they mop up reactive molecules in a test tube. Some rat studies report effects on sex hormone levels, sperm quality and stamina. The herb also holds a lot of soluble fibre-like carb. That is the most likely reason it softens stools a little. None of this has been confirmed in human volunteers. Effects seen in rats at high doses often do not carry over to people. What forms does Suo Yang come in? Suo Yang is sold in several forms. All of them are made from the dried stem: Dried sliced stem, simmered in water to make a decoction (a strong herbal tea). This is the classic form. Granules or instant powder, stirred into hot water. Capsules or tablets of powdered herb or of a strong extract. Medicinal wine or tincture, where the herb is soaked in alcohol. This is a common folk preparation. As one herb in a multi-herb TCM formula. This is how a practitioner most often prescribes it. Products are not set to a standard marker compound. So strength is not comparable between brands. Where it comes from: Suo Yang came into the Chinese materia medica fairly late. It is first clearly described in the Ben Cao Yan Yi Bu Yi, a Yuan dynasty text from the 1300s. It turns up again in Ming dynasty works, including the Ben Cao Gang Mu. It grows as a parasite on the roots of desert shrubs in northwest China, Mongolia and Central Asia. It was gathered in spring, when the red, club-shaped stem pushes up through the sand. It has stayed a standard kidney-yang tonic in Chinese practice ever since. It is usually paired with Yin Yang Huo (epimedium) or Rou Cong Rong. Related Cynomorium species have their own folk histories in North Africa and Malta.

Helps

What does Suo Yang help with? Low sexual desire and erectile difficulty: This is the best-known traditional use, and it is the least tested. Classical texts recommend Suo Yang for "impotence" from kidney yang deficiency, usually inside a multi-herb formula rather than alone. The modern support is animal work: some rodent studies report changes in testosterone levels and mating behaviour. No published human trial tests Suo Yang alone for erectile difficulty, so its effect in people is unknown. Erectile problems can be an early sign of heart disease or diabetes. See a doctor about the cause before treating it with herbs. Dry, hard stools in older or frail people: This is the traditional use with the most believable basis. Suo Yang is classed as an herb that "moistens the intestines", and it is rich in soluble plant carbohydrate, which holds water in the stool. Even so, the effect is mild and has not been measured in a human trial. Plain fibre, fluid and, if needed, a pharmacy laxative have far better evidence. If your stools are loose to begin with, this herb is the wrong choice and may make things worse. Lower back and knee weakness or aching: In TCM, chronic (long-lasting) aching and weakness in the lower back and knees is read as a sign of kidney deficiency, and Suo Yang is a standard herb for that pattern. There is no human trial evidence that it helps back or knee pain from any cause. Laboratory studies suggesting effects on bone cells are early-stage and do not predict results in people. Persistent back pain needs a proper diagnosis, not a tonic. Fatigue with feeling cold: Traditional practice uses Suo Yang for people who tire easily, feel cold and have low drive — the "yang deficiency" picture. Animal studies have looked at swimming endurance and fatigue markers in mice, with mixed results. This does not translate into evidence for human tiredness. Persistent fatigue with cold intolerance can mean an underactive thyroid or anaemia (low red blood cells), both easily checked with a blood test. Male fertility concerns: Some rodent studies report improved sperm count or motility (how well sperm move) after Cynomorium extracts. That is the extent of it. No human fertility trial of Suo Yang has been published that we can identify. Fertility problems involve both partners and deserve medical assessment rather than self-treatment. Do not delay a fertility work-up in order to try herbs first.

Suo Yang

Quick Facts

  • What it is: Suo Yang is a single TCM herb — the dried stem of the desert plant Cynomorium songaricum, also known as Cynomorium stem — used traditionally as a warming kidney tonic and a mild stool softener.
  • Main uses: Low sexual desire and erectile difficulty (traditional), Dry, hard stools (traditional), Lower back and knee weakness (traditional), Tiredness with feeling cold (traditional)
  • Best for: People working with a qualified TCM practitioner who want a traditional kidney-yang tonic, Traditional use for dry stools in older adults
  • Active ingredients: Triterpenes including ursolic acid, Flavonoids and proanthocyanidins, Tannins, Polysaccharides and soluble fibre
  • Forms: Dried sliced stem for decoction, Granules or instant powder, Capsules and tablets, Medicinal wine or tincture, Ingredient in multi-herb formulas
  • Time to effect: Not established in people; traditional use assumes two to four weeks of steady dosing.
  • Side effects: Usually mild and gut-related — loose stools, stomach ache, dry mouth; long-term safety in people is untested.
  • Pregnancy & breastfeeding: Avoid in pregnancy and while breastfeeding.

Educational information, not medical advice — ask your doctor or midwife.

Track this remedy in the app

Track Suo Yang with reminders and record whether it helped, in the app.

Download on the App StoreGet it on Google Play

What is Suo Yang?

Suo Yang is the dried, fleshy stem of a desert plant, Cynomorium songaricum. It is also called Cynomorium stem. It is used as a single herb in Traditional Chinese Medicine (TCM).

In tradition it is given to people said to have "kidney yang deficiency". That is a TCM pattern of feeling cold, tired and weak in the lower back and knees, with low sex drive. It is also given to soften dry, hard stools in older or frail people.

Here is the evidence verdict up front. Almost all research on Suo Yang is lab and animal work. We could not find published human trials that test it on its own for any of its traditional uses, so its effects in people are unproven.

Long use and scientific proof are two different things. Suo Yang has a long, well-recorded place in Chinese herbal medicine, but that history does not show that it works.

This page reports both points separately. You will not see that caution repeated in every section below.

How does Suo Yang work?

Nobody has shown how Suo Yang works in people. The honest answer is that we do not know.

In TCM theory it is said to "warm and boost kidney yang", feed essence and blood, and moisten the gut. These are traditional ideas about body patterns. They are not things we can measure in a lab.

Lab and animal studies point in a few directions. Extracts show antioxidant action, which means they mop up reactive molecules in a test tube. Some rat studies report effects on sex hormone levels, sperm quality and stamina.

The herb also holds a lot of soluble fibre-like carb. That is the most likely reason it softens stools a little.

None of this has been confirmed in human volunteers. Effects seen in rats at high doses often do not carry over to people.

What forms does Suo Yang come in?

Suo Yang is sold in several forms. All of them are made from the dried stem:

Dried sliced stem, simmered in water to make a decoction (a strong herbal tea). This is the classic form.

Granules or instant powder, stirred into hot water.

Capsules or tablets of powdered herb or of a strong extract.

Medicinal wine or tincture, where the herb is soaked in alcohol. This is a common folk preparation.

As one herb in a multi-herb TCM formula. This is how a practitioner most often prescribes it.

Products are not set to a standard marker compound. So strength is not comparable between brands.

Where it comes from:

Suo Yang came into the Chinese materia medica fairly late. It is first clearly described in the Ben Cao Yan Yi Bu Yi, a Yuan dynasty text from the 1300s. It turns up again in Ming dynasty works, including the Ben Cao Gang Mu.

It grows as a parasite on the roots of desert shrubs in northwest China, Mongolia and Central Asia. It was gathered in spring, when the red, club-shaped stem pushes up through the sand.

It has stayed a standard kidney-yang tonic in Chinese practice ever since. It is usually paired with Yin Yang Huo (epimedium) or Rou Cong Rong. Related Cynomorium species have their own folk histories in North Africa and Malta.

Who should avoid Suo Yang?

  • Do not use if you are pregnant or trying to become pregnant, as the effects on pregnancy have never been studied.
  • Do not use if you are breastfeeding.
  • Do not give it to children.
  • Do not use if you have diarrhoea, loose stools, or any ongoing bowel condition such as Crohn's disease or ulcerative colitis (long-term inflammation of the bowel).
  • Do not use if you have a fever or an active infection.
  • Do not use if a TCM practitioner has told you that you have a yin deficiency with heat pattern, or a damp-heat pattern — the traditional texts class this herb as wrong for both.
  • Do not use if you have a hormone-sensitive cancer such as prostate or breast cancer, unless your cancer doctor has agreed.
  • Do not use if you take warfarin or another blood thinner, unless your doctor has reviewed it.
  • Avoid it if you are within two weeks of planned surgery, because of the possible effect on blood clotting.
  • Do not use it in place of medical care for erectile difficulty, infertility, ongoing constipation or persistent back pain — each of these needs a diagnosis first.

When should you see a doctor?

See a doctor promptly if you get diarrhoea that lasts more than two days, severe stomach pain, or signs of dehydration such as dizziness and passing very little urine.

Stop the herb and get urgent medical help if you notice yellowing of the skin or eyes, dark urine, unusual bruising or bleeding, or a spreading rash with swelling of the face, lips or throat.

Book a normal appointment before starting if you take any prescription medicine, if you have diabetes, or if you have a heart, liver or kidney condition. Erectile difficulty, ongoing constipation, unexplained weight loss and persistent fatigue all deserve a proper check rather than a tonic.

Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.

Remedies related to Suo Yang

The evidence behind this remedy, in one page

What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.

One email with the summary. We'll also send a short weekly evidence update — unsubscribe any time.