scruple (apothecary)

What Is scruple (apothecary)?

A scruple in the apothecary system is a small unit of mass that doctors and pharmacists once used to weigh medicines. It is much smaller than an ounce and is now mostly a historical unit.

Definition

In the old apothecary system of weight, a scruple is defined by grains and by its place among other units.

• 1 scruple = 20 grains
• 3 scruples = 1 dram (also written drachm)
• 24 scruples = 1 apothecary ounce

In modern metric units this is:

• 1 scruple ≈ 1.296 grams
• You can round this to about 1.3 grams for simple everyday use.

History / Origin

The word scruple comes from the Latin word scrupulum. It meant a small sharp stone or a tiny weight. The Romans used scrupulum as a unit in their own system of weights.

Later, doctors and pharmacists in Europe used the scruple in the apothecary system. This system helped them measure medicines more exactly. It stayed in use from the Middle Ages through the 19th century, especially in countries that used English law, like Britain and the early United States.

Over time, the metric system became the world standard. Doctors and pharmacists moved from scruples and grains to grams and milligrams. By the 20th century, most countries had officially replaced the apothecary system with metric units for medical work.

Symbol & Abbreviation

The scruple has its own traditional sign and several short forms.

• Main symbol: ℈ (a special character for scruple)
• Common short forms in texts: scr or sc
• Sometimes a simple s was also used in handwritten recipes or prescriptions.

On old medicine bottles or prescriptions you might see amounts written like ℈ ii which means 2 scruples.

Current Use Around the World

Today, the apothecary scruple is almost never used in modern medicine. Most countries and health systems now use grams and milligrams instead.

You may still meet the scruple in these situations:

• Old medical books or historical prescriptions
• Collections of antique pharmacy equipment
• Some traditional herbal or folk medicine recipes
• Discussions of troy weight for precious metals, where a troy scruple has the same size, 20 grains

For everyday science, school, pharmacy and hospitals, the scruple is considered an outdated unit, and the metric system is preferred.

Example Conversions

These examples show how to change scruples into other units and back again. Values are rounded for easy use.

Scruples to grams

• 1 scruple ≈ 1.3 g
• 2 scruples ≈ 2.6 g
• 3 scruples ≈ 3.9 g (this is also 1 dram)
• 5 scruples ≈ 6.5 g
• 10 scruples ≈ 13 g

Grams to scruples

• 1 g ≈ 0.77 scruple
• 5 g ≈ 3.9 scruples (about 4 scruples)
• 10 g ≈ 7.7 scruples (about 8 scruples)

Scruples to grains

• 1 scruple = 20 grains
• 3 scruples = 60 grains (1 dram)
• 24 scruples = 480 grains (1 apothecary ounce)

Scruples to drams and ounces

• 1 dram = 3 scruples
• 1 apothecary ounce = 8 drams = 24 scruples

Related Units

The scruple belongs to a family of old weight units used in apothecary and troy systems.

• Grain small base unit of mass, 1 scruple = 20 grains, used in bullets, medicine and jewelry weights.
• Scruple 20 grains, the unit explained on this page.
• Dram (drachm) 3 scruples or 60 grains, a larger apothecary unit once used for medicines.
• Apothecary ounce 8 drams or 24 scruples or 480 grains.
• Troy ounce unit for precious metals, also based on grains, related to the same grain and scruple size.
• Gram main metric unit of mass used today, about 0.77 of a scruple.
• Milligram one thousandth of a gram, used for very small doses in modern medicine.

FAQs

Is the apothecary scruple still used in modern pharmacy

No. Modern pharmacy almost always uses metric units such as grams and milligrams. The scruple is now mostly of interest for history, not for real life dosing.

How many grams are in one scruple

One scruple is about 1.296 grams. For simple math you can use 1.3 grams.

How many scruples are in a dram

There are 3 scruples in 1 dram in the apothecary system.

How many scruples are in an apothecary ounce

There are 24 scruples in 1 apothecary ounce.

Is the apothecary scruple the same as the troy scruple

Yes. Both are equal to 20 grains. They share the same size, but are used in different systems. Apothecary scruples were for medicines, troy scruples are linked to precious metals.

Why did people stop using scruples

Countries slowly changed to the metric system because it is simpler and more consistent. Using grams and milligrams reduces confusion and errors in science and medicine.

Can I safely use old prescriptions that mention scruples

No. You should never follow an old prescription that uses scruples or any other old unit. Always ask a modern doctor or pharmacist and use current medical advice.