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Limited evidenceMen's health

Cynomorium (Suo Yang)

A parasitic desert plant used in Chinese medicine as a yang tonic for stamina and sexual function. The modern literature is almost entirely rodent and cell work on its polysaccharides and triterpenes; no controlled human trial supports the marketed uses.

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What the science says

  • PDE5 inhibition shown only in animals Limited evidence

    A 2026 study reported that Cynomorium songaricum polysaccharides inhibit phosphodiesterase-5 and improved erectile parameters in a rat model. The mechanism is plausible and the same one sildenafil uses, but the finding has not been tested in humans.

  • Broad preclinical activity, no clinical translation Limited evidence

    A 2026 review of Cynomorium polysaccharides summarizes antioxidant, immunomodulatory and metabolic effects across cell and animal models. Reviews of this kind repeatedly conclude that human clinical data are lacking.

Dosage & safety

Studied doseNo validated human dose. Traditional decoctions use roughly 5–10 g of dried stem; extract capsules typically state 500 mg once or twice daily as a label dose.
SafetyHuman safety data are sparse. Traditional texts caution against use with diarrhoea or in what they classify as heat patterns. Given the reported PDE5 activity in animals, avoid combining with nitrates or erectile dysfunction drugs. Avoid in pregnancy and breastfeeding, and in people on antihypertensives until interactions are studied.

How to take it

TimingTiming does not matter.
With food?Take it with food; the dried stem preparations are commonly reported to upset an empty stomach.
Worth knowingTraditional practice avoids it during diarrhoea, and the crude stem is mildly laxative in some people.

Interactions

With medications

  • nitrates and PDE5 inhibitors such as sildenafil

    Animal work reports PDE5-like activity, which could add to these drugs and drop blood pressure. Do not combine, particularly with nitrates

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does cynomorium help erectile dysfunction?

Not shown in humans: cynomorium (suo yang) polysaccharides inhibited PDE5 and improved erectile parameters in a 2026 rat study, but no controlled human trial supports the marketed uses. The evidence grade is limited.

Can you take cynomorium with sildenafil or nitrates?

No. Animal work suggests cynomorium has PDE5-like activity that could add to sildenafil or nitrates and drop blood pressure, so do not combine them, particularly nitrates.

How much cynomorium per day?

There is no validated human dose of cynomorium; traditional decoctions use roughly 5–10 g of dried stem, and extract capsules state 500 mg once or twice daily as a label dose.

Scientific references

Related in Men's health

Herbal medicines: what the evidence says (335)