"Look up how many formulas it appears in before you buy" — sound advice, with three traps in it

A 34-reply thread on r/DIYfragrance taught a purchasing method: ignore the supplier's recommended starter list, look up how many formulas a material actually appears in and what dose range it sits at, then decide whether to order and how much. The poster gave examples — one material turning up in five hundred-odd formulas, often above 10%; another appearing once, under 0.1%.

The method is sound. I ran it, and hit three traps nobody in the thread mentioned.

The short version

• Across 954 deduplicated public formulas, 2,381 distinct materials appear. 44.7% of them appear in exactly one formula.
• Linalool tops the list at 35.4% of formulas. But the top 10 together cover only 13.3% of all material slots, and it takes 603 materials to reach 82.4%. There is no universal shopping list.
• Three traps: one molecule filed under two names, naturals split across origin variants, and rows that are pre-dilutions rather than neat material. All three distort the ranking.

About a 10 minute read.

The ranking itself

Same corpus as the previous article. Trailing pre-dilution markers were stripped before counting; solvent rows are excluded.

Rank	Material	Formulas	Share	Median dose
1	Linalool	338	35.4%	5.93%
2	Benzyl acetate	317	33.2%	5.00%
3	Phenethyl alcohol	274	28.7%	10.00%
4	Coumarin	225	23.6%	2.34%
5	Citronellol	220	23.1%	5.94%
6	Linalyl acetate	207	21.7%	5.56%
7	Geraniol	192	20.1%	5.84%
8	Hedione	165	17.3%	7.00%
9	Hydroxycitronellal	161	16.9%	8.00%
10	Eugenol	161	16.9%	1.70%
11	Benzyl salicylate	159	16.7%	9.47%
12	Alpha-hexyl cinnamaldehyde	157	16.5%	8.00%
13	Lilial	151	15.8%	6.00%
14	Heliotropin	140	14.7%	3.00%
15	Dihydromyrcenol	140	14.7%	6.11%

The dose column is more useful than the rank. Both are top ten, yet phenethyl alcohol's median is 10% and eugenol's is 1.70%. Fifty grams of the first might last two months; ten grams of the second can last years.

Trap one: one molecule, two names

Rank 8 is hedione at 165 formulas. Rank 30 is methyl dihydrojasmonate at 84. Same molecule; the first is Firmenich's trade name.

Combined, 249 formulas — past coumarin at rank 4, moving it from eighth to third.

Read the ranking naively and you underestimate it by half. This is the problem from material names mislead showing up in a purchasing decision: trade name and systematic name coexist, and which one a formula author uses is habit.

The people writing the papers hit the same mine. When Kemicha and colleagues analysed the ingredient lists of 300 moisturisers on the Tunisian market for Contact Dermatitis in 2026, their methods section states that all seven targeted allergen classes were searched under every relevant synonym in both English and French. Anyone doing ingredient counts knows to guard against this. People doing purchasing decisions routinely forget.

Trap two: naturals split across origins

Cedarwood is not one name in this corpus. It is five: cedarwood oil virginia (29 formulas), cedarwood oil atlas (5), cedarwood oil white (4), cedarwood oil texas (4), cedarleaf oil (3), plus stragglers. Total 58, while the largest single name reads 29.

The same happens across the naturals:

Group	Distinct names	Total formulas	Largest single name
Cedarwood	5+	58	29
Sandalwood (incl. synthetic replacers)	5+	131	60
Jasmin (incl. dilution grades)	5+	109	23
Vetiver (incl. vetiveryl acetate)	5+	84	34
Ionone family	5+	402	107

Synthetics usually carry one name. Naturals fragment by origin, plant part and extraction method. Comparing ranks directly therefore understates naturals and overstates synthetics, systematically.

To dodge it, search by group rather than by exact name, then decide for yourself whether to merge the origins. There is no correct answer here — Haitian and Bourbon vetiver genuinely differ.

Trap three: some rows are pre-dilutions

The dose column looks straightforward until you notice that some rows are not neat material at all.

Material	Listed as a pre-dilution	Share	Median dose
Alpha-isomethyl ionone	49 of 49	100%	5.56%
Aldehyde C-11 undecylenic	45 of 59	76.3%	1.00%
Phenylacetaldehyde	43 of 57	75.4%	1.00%
Indole	65 of 88	73.9%	0.68%
Oakmoss absolute	24 of 37	64.9%	2.87%
Alpha-damascone	31 of 59	52.5%	0.56%
Rose oxide	29 of 68	42.6%	0.50%

Indole reads 0.68%, but in three appearances out of four that 0.68% is a dilution, which puts the neat material at 0.068% or lower.

This column is the most actionable signal in the whole exercise. A material that is almost always used pre-diluted is one you buy in the smallest pack available, then dilute to a 1% or 10% stock the day it arrives. Buy 25 grams of indole and most people will never finish it, while it slowly darkens in the bottle.

Frequent doesn't mean sufficient

The top 10 cover 13.3% of slots.

Top N materials	Slots covered
10	13.3%
20	21.5%
50	35.2%
100	48.2%
200	62.0%
603	82.4%

Set this beside the finding from the previous article and you get a slightly counterintuitive pair: a single formula leans on a median of 10 materials for 90% of its weight, but across formulas, which 10 changes every time.

Which means the "twenty materials that do everything" list does not exist. What exists is "each direction has its handful of regulars". So buy by direction, and stop working down the leaderboard from the top.

It caught our own list too

Running the ranking back against this site's 47-material starter palette does not flatter us: only 24 of the top 50 are on our list.

Among the misses, rank 9 — hydroxycitronellal — appears in 16.9% of formulas at a median 8%, and we have never written about it. Benzyl salicylate (11) and alpha-hexyl cinnamaldehyde (12) are in the same position.

Running the other way, some of our picks are marginal in the corpus: alpha-irone at 12 formulas, menthol at 10 across name variants, myrrh at 8.

Neither side is a mistake. A starter list picks what teaches well — alpha-irone earned its place explaining ageing, menthol earned its place explaining the TRPM8 receptor. The gap is still worth writing down: our list is ordered by teaching value, not by how often working perfumers reach for the material, and readers buying from it were never told that. Hydroxycitronellal is now on the queue.

Frequent doesn't mean safe either

Geraniol ranks 7th here, at a median dose of 5.84%.

Jongeneel and colleagues published a health impact assessment in Environment International in 2019, building a simulated population from multiple product-use surveys. They estimate that current dermal exposure produces 34 new cases of geraniol contact allergy per million consumers per year in Western and Northern Europe, with roughly twice as many (60 per million) suffering clinical symptoms on re-exposure, mainly driven by household cleaning products. Restricting geraniol concentrations to below 0.01% would noticeably reduce both.

Those two numbers cannot be subtracted from each other, because their bases differ. 5.84% is the share inside a fragrance concentrate; 0.01% refers to concentration in the finished consumer product. A fine fragrance is roughly 15% to 20% concentrate; a lotion or cleaner is usually under 1%. Very roughly, the same concentrate puts geraniol at about 0.9% to 1.2% of a finished perfume, and about 0.03% in a lotion dosed at 0.5% fragrance. Treat that arithmetic as an order of magnitude, not a number — the real figure depends on the actual concentrate and the actual dosage.

The point stands: a frequency table answers how often people reach for something. It says nothing about whether your dose in your product is legal or safe. That means current IFRA Standards and the rules of your market, which is a different piece of work.

This corpus is a historical document

Rank 13 is Lilial (butylphenyl methylpropional), in 15.8% of formulas at a median 6%.

It is no longer usable in the EU. Regulation (EU) 2021/1902 added it as entry 1666 of Annex II to the Cosmetics Regulation on the grounds of a CMR category 1B classification, applicable from 1 March 2022, across every cosmetic placed on the EU market, perfume included.

The same table also carries musk ketone at rank 29 and oakmoss absolute, each with its own IFRA restriction.

So read the table this way: it tells you what was used a lot historically, not what you can use today. Spot a material you want, check its current regulatory status, then order.

How to actually use this

Three steps.

Pick a direction before you check frequency. Building a citrus fougère means looking at that direction's regulars, not working down the overall leaderboard. The overall top ten spans rose, white floral, lavender and gourmand; bought together they do not become anything.

Let the median dose size the order, not the rank. A material with a median of 8% and one with a median of 0.5% behave completely differently at the same 10 grams — three uses versus three years.

Let the pre-dilution share pick the pack size. Anything above half in that column: smallest pack, and make a stock solution first.

What this doesn't establish

74% of the corpus carries a patent or source row. A patent example is not a commercial formula; it may be simplified, or written broad to cover ground. The ranking reflects the habits of this set of public demo formulas.

The time span is unknown. Lilial at 15.8% shows the corpus holds a substantial share of older formulas, but the pages carry no consistent date, so I could not compute a year distribution or split the set into older and newer for comparison.

Name normalisation only stripped pre-dilution markers. Trade-versus-systematic names and the origin variants of naturals were reconciled by hand and named in the text, not merged automatically. The ranking above therefore still carries the bias from traps one and two, deliberately — the point was to show what reading the names straight actually gets you.

The corpus has no prices. Frequency and dose tell you how much to buy. Whether you can afford it is a separate question for the supplier pages.

References

D. Kemicha et al., Allergic Risk of Moisturising Cosmetic Products: A Study on the Composition of 300 Products Commercialised in Tunisia, Contact Dermatitis, 94(6), 645–651 (2026). PMID 41692689. doi:10.1111/cod.70096

W. P. Jongeneel et al., Health impact assessment of a skin sensitizer: Analysis of potential policy measures aimed at reducing geraniol concentrations in personal care products and household cleaning products, Environment International, 118, 235–244 (2019). PMID 29890471. doi:10.1016/j.envint.2018.04.039

Regulation (EU) 2021/1902, amending Annex II to Regulation (EC) No 1223/2009; butylphenyl methylpropional listed as entry 1666, applicable from 1 March 2022.

Related: The pyramid says 28 notes, the brand says 6, Material names mislead, The starter palette, mapped.