What is Guipan?

Guipan is the dried belly shell of the Reeves' turtle (Mauremys reevesii). It is also called tortoise plastron. Korean healers grind it to powder or boil it down into a stiff glue.

It is used as a tonic. A tonic is a remedy meant to build up a body that feels worn out. Guipan is given most often for night sweats, hot flushes, weak bones and heavy periods.

Here is the verdict up front. We could find no human trials of Guipan. It has a long, firm place in East Asian medicine, but long use is not proof that a remedy works.

How does Guipan work?

No one has shown how Guipan works in a person. Most of the shell is calcium salts and protein. So a dose may act a bit like a calcium and gelatin supplement, though that idea has not been tested.

In Korean medicine, Guipan is said to feed the yin. Yin is a traditional idea, not a body part. The picture is of a body that has run hot and dry, and the shell is meant to cool and moisten it.

Lab and animal work hints at effects on bone cells and on the immune system (the body's defence system). That work is early. It does not tell you what a dose will do in you.

What forms does Guipan come in?

You will meet Guipan in four main forms. Raw shell comes as cleaned, broken pieces meant for long boiling.

Vinegar-fried shell is the common pharmacy form. The shell is heated, quenched in vinegar and crushed, which makes it easier to break down in water.

The glue form is called gyo. The shell is simmered for a day or more and the liquid is set into hard blocks that melt in hot water.

Powders, pills and granules are also sold. In practice Guipan is nearly always one part of a mixed formula, not a stand-alone product.

Where it comes from:

Tortoise plastron is an old drug. It appears in the Shennong Bencao Jing, a Chinese herb book from roughly 2000 years ago.

Korean medicine took it up and kept it. It is listed in the Dongui Bogam, the great Korean medical text finished in 1613. Japanese Kampo doctors used it as well.

Today the Reeves' turtle is endangered. Trade is limited by law in many countries. Some makers now use farmed turtles, so check the label and the paperwork before you buy.

What does Guipan help with?

• Night sweats and hot flushes: This is the classic reason Korean practitioners reach for Guipan. It is used for people who feel hot at night, sweat in their sleep and wake dry. No human trial has tested Guipan for this, so the support is tradition only.
• Weak or thinning bones: The shell is rich in calcium salts, and tradition uses it for weak backs, knees and bones. Lab work has looked at turtle shell extracts and bone cells. There is no human trial showing it protects bone or lowers the chance of a fracture.
• Heavy or long menstrual bleeding: Old texts use Guipan in formulas for bleeding that goes on too long. This use is traditional and untested in trials. Heavy bleeding needs a medical check first, because the cause matters more than the remedy.
• Restless sleep with a hot, dry feeling: Guipan appears in calming formulas for people who feel wired, hot and unsettled at night. We found no sleep trials of Guipan on its own. Treat this as tradition, not evidence.
• Low fever that drags on after an illness: Classical practice uses Guipan for a slow, low fever that lingers once an illness has passed. There is no trial evidence for this. A fever that will not go away should be checked by a doctor.
• Slow growth or late teething in children (traditional use only): Old Korean and Chinese texts list this use. There is no modern evidence behind it, and children are the group most at risk from any lead in an animal shell. Do not give Guipan to a child on your own.

Which foods are rich in Guipan?

1. No everyday food contains Guipan: it comes only from the shell of the Reeves' turtle
2. Sardines and canned fish with soft bones: a food source of the same calcium salts
3. Dairy foods such as milk and yoghurt: everyday calcium
4. Slow-cooked bone broth: a food source of gelatin, the protein you get from boiled shell

Practical Tips:

If you want the calcium and gelatin, ordinary food gives you both without the heavy metal or conservation worries.

What are the side effects of Guipan?

• Upset stomach or a heavy, full feeling
• Bloating and wind
• Loose stools or diarrhoea
• Loss of appetite
• A strong fishy taste and smell that some people cannot take
• Rash, itching or swelling in people allergic to animal protein
• Constipation, from the calcium in the shell
• Build-up of lead or other heavy metals with long use of untested product

Good to know:

Most reported trouble is mild. Stomach upset is the usual complaint, because the powder is hard to digest. It normally settles once you stop.

Two problems matter more. An allergy to the animal protein can bring a rash or swelling, and long use of untested shell can add to the lead in your body. Both are reasons to buy tested product and to take breaks.

How much Guipan should you take?

• Recommended daily: No trial has set a dose for Guipan, so every figure below comes from practice, not proof. In Korean and Chinese clinics the dried shell is used at about 9 to 24 grams a day. It is boiled in water for a long time, usually 30 minutes or more before the other herbs go in. The glue form (gyo) is used at about 3 to 9 grams a day, melted into hot liquid. Powders and pills follow the maker's label. Use Guipan only under a trained Korean medicine practitioner who knows the rest of your medicines.
• Best time of day: Split the daily amount into two doses, usually morning and evening. If you take it for night sweats, tradition favours the evening dose.
• With or without food: Take it with or just after food. The powder is heavy and can upset an empty stomach. Keep a gap of at least two to four hours between Guipan and any medicine listed under drug interactions.
• Time to effect: There is no reliable answer, because no trial has measured it. Practitioners usually expect two to four weeks before any change, and they judge tonics over months.
• How long to take it: Guipan is treated as a slow tonic, not a quick fix. Courses usually run a few weeks to a few months. Review how you feel at four to six weeks. If nothing has changed, stop and rethink rather than pushing on. Do not take it non-stop for more than about three months without a review. Longer use means more exposure to any heavy metal in the shell.