Table of Contents

• Before calculating, identify the whole and the part
• 1. Turn a percentage into a milligram amount
• 2. Work backwards from a declared constituent amount
• 3. Keep the serving basis attached to the answer
• 4. Compare concentration without confusing it with total amount
• 5. Spot the calculation you cannot legitimately make
• A short check before comparing real labels
• Frequently Asked Questions

Last Updated: October 28, 2026

A label can show an extract weight, a percentage and a constituent amount without any of them being competing answers. The difficulty is knowing what each number measures.

These five Griffonia extract label examples explain the arithmetic. Every quantity below is invented for teaching, not taken from a product and not a suggested dose. The calculations assume the stated percentage is a mass percentage of the named constituent in the stated extract. If a real label does not make that basis clear, ask the manufacturer rather than guessing.

Before calculating, identify the whole and the part

An extract amount and the amount of a named constituent within it are different quantities. A percentage expresses a part relative to a whole. For these examples, the whole is the extract mass and the part is the stated 5-HTP mass.

The NIH Office of Dietary Supplements explains that botanical standardisation involves measuring selected chemicals and adjusting preparations for consistency. That explanation helps distinguish a constituent percentage from a general botanical name. Its discussion of US regulation should not be read as UK labelling law.

Our arithmetic describes what the imaginary wording says. It does not establish what an actual bottle contains, whether a test is reliable, or whether a supplement is suitable for anyone. A calculator can multiply a claim; it cannot verify one.

1. Turn a percentage into a milligram amount

Imagine a teaching label stating: “200 mg Griffonia extract, containing 20% 5-HTP by mass.” Twenty per cent means twenty parts in every hundred, or 0.20.

200 mg × 0.20 = 40 mg.

The calculated 5-HTP quantity is 40 mg within the 200 mg of extract. It is not another 40 mg to add on top of that extract weight. Writing 240 mg would count the part twice.

A quick check is to ask whether the answer could fit inside the whole. With the assumptions given here, a constituent amount larger than the extract amount would signal a mistake in the calculation or its starting information.

2. Work backwards from a declared constituent amount

Now imagine 300 mg of extract with a declared 45 mg of 5-HTP, both referring to the same serving. To calculate the implied percentage, divide the part by the whole and multiply by one hundred.

45 mg ÷ 300 mg × 100 = 15%.

The matching milligram units cancel in the division. If one quantity were shown in grams and the other in milligrams, convert them first: one gram is one thousand milligrams.

This is a consistency check on the imaginary numbers. It is not proof of standardisation, manufacturing quality or laboratory results. Those are separate questions requiring information beyond this division.

3. Keep the serving basis attached to the answer

Suppose a hypothetical panel gives 240 mg of extract per two-capsule serving and states 25% of the named constituent by mass. The calculation is 240 × 0.25, giving 60 mg per stated serving.

If, and only if, the two capsules contain equal amounts, the corresponding figure is 30 mg per capsule. Without that assumption, simply dividing by two is not justified.

Write the basis beside every result: “60 mg per stated two-capsule serving.” A bare “60 mg” can be copied into a comparison and quietly change meaning. This example explains units, not how many capsules anyone should take.

4. Compare concentration without confusing it with total amount

Two fictional extracts can have different percentages yet the same calculated constituent amount. Consider 150 mg at 20%, and 300 mg at 10%.

150 × 0.20 = 30 mg; 300 × 0.10 = 30 mg.

The first is more concentrated in the named constituent under our assumptions. The calculated quantity is nevertheless the same because the second extract amount is larger.

This does not make the preparations interchangeable or equally suitable. It establishes one numerical equality and nothing more. Percentage, extract mass, composition and suitability are different questions. “Higher percentage” is not a complete comparison.

5. Spot the calculation you cannot legitimately make

Imagine the label says “100 mg extract, 10:1” but gives no 5-HTP percentage or amount. You cannot calculate its 5-HTP content from that ratio alone.

The NIH botanical background guide distinguishes botanical-to-extract ratios from information about measured constituents. A ratio describes a relationship between botanical starting material and an extract, with the exact meaning depending on how it is stated. It is not automatically a constituent concentration.

Do not turn 10:1 into 10% or assume it means ten times a particular constituent. The missing information is the named constituent amount or a clearly defined percentage for the relevant extract. “Cannot determine from the information supplied” is a correct answer, even if it feels less satisfying than a number.

A short check before comparing real labels

Read the ingredient name, the quantity, the units, the serving basis and what the percentage refers to. Keep those details together when asking a manufacturer a question.

For example: “Does this percentage apply to the listed extract mass, and are both figures per the same stated serving?” That is more useful than asking whether a number is strong.

These examples are deliberately about reading information, not choosing a supplement or changing its use. For suitability, particularly alongside medicines, ask a pharmacist or another appropriate health professional. Keep the arithmetic in its lane: clear numbers are helpful, but they are not a health recommendation.