Myristyl Myristate
Myristyl myristate (INCI name Myristyl Myristate) is rated 5 on our list, in the high band, and the number is traced: Fulton 1989 graded it 5 and Morris and Kwan 1983 graded it 0 to 1.
Like every rating here, it is for the raw ingredient tested alone, and a label does not print how much of it a product holds.
Is myristyl myristate comedogenic?
Myristyl Myristate is rated 5 on the comedogenic scale, which is the high band.
A waxy ester used in lotions to give a rich texture.
- Comedogenic rating
- 5 out of 5
- Band
- High: Clear plugging in the rabbit-ear test. The first band to check in a leave-on product.
- Where the number comes from
- Traced to Fulton 1989 and Morris and Kwan 1983. The section on who rated it prints each grade.
- Composition
- Ester / Fatty Acids & Derivatives
- Also written as
- No common variants recorded
What a 5 means in practice
A 4 or 5 is the top of the scale. In the rabbit-ear test, Fulton 1989 counted 4 to 5 as a clear positive: the ingredient plugged the follicles, and did so repeatably. A person's skin reacts less readily than a rabbit's ear, and a product holds far less of the ingredient than the test did, so treat this band as the first thing to check in anything that stays on your skin. It does not prove the ingredient will cause a breakout. A rinse-off product is on the skin for seconds.
Two things change what this number is worth. Ingredients are listed in descending order of concentration, so myristyl myristate near the top of a label matters far more than myristyl myristate at the bottom. And the rating describes the raw ingredient on its own. A 2006 review in the Journal of the American Academy of Dermatology found that a rating for a single ingredient does not reliably predict how a finished formula behaves on human skin. The full story of the scale is here.
Who rated it
Our list gives myristyl myristate 5. These are the figures the published rabbit-ear studies we have read give it, as printed in each paper's table.
| Paper | Grade | Tested as |
|---|---|---|
| Fulton 1989 | Grade 5 | Tested as Myristyl myristate |
| Morris and Kwan 1983 | Grade 0 to 1 | Tested as Myristyl Myristate (50% in mineral oil) |
Ahn and colleagues 1985 reports severe comedogenicity in the rabbit ear canal, in an abstract that gives no 0 to 5 grade.
Our list's figure is within what these papers report.
Fungal acne
Myristyl Myristate matches rule 2, ester of a C12 to C24 fatty acid , on the fungal acne checker. An ester of myristic acid, C14. The rule comes from lab studies of what Malassezia yeast can feed on, and it is not a verdict on any product.
What safety reviewers say
The rating above is about pore plugging in a rabbit-ear test. Whether myristyl myristate is safe to use in cosmetics is a separate question. Below is the conclusion of the Cosmetic Ingredient Review (CIR), a US expert panel, and what the EU ingredient database, CosIng, lists for it. We quote CIR's conclusion as written, read on 31 October 2026.
- Cosmetic Ingredient Review (US)
- In a 2015 review of 237 alkyl esters, myristyl myristate among them, the panel concluded they are “safe in the present practices of use and concentration described in this safety assessment when formulated to be nonirritating”. Safety Assessment of Alkyl Esters as Used in Cosmetics, 2015 (opens in a new tab)
- Pore plugging in the same report
- The report’s summary table says the undiluted material “produced comedogenic activity in rabbit ears”.
- What it does in a product (EU CosIng)
- Listed as MYRISTYL MYRISTATE: skin conditioning (emollient), opacifying. CosIng entry (opens in a new tab)
- EU restrictions
- None. CosIng shows no entry for it in the annexes of the EU Cosmetics Regulation.
What we make of this. CIR's conclusion does not grade pore plugging, so on its own it neither confirms nor contradicts the 5 on our list. The report does print one pore-plugging result, quoted above, and we give it as one more data point beside our rating. A safety review looks at things like irritation, allergy and toxicity at the amounts products use, and the rating is only about pores, so read them side by side.
Common questions
- Is myristyl myristate comedogenic?
- Myristyl Myristate is rated 5 on the comedogenic scale, which is the high band.
- Is myristyl myristate non comedogenic?
- No. Myristyl Myristate is rated 5 on the comedogenic scale, which is the high band. That is a published rating for the ingredient rather than a verdict on any product containing it.
- What is myristyl myristate's comedogenic rating?
- 5 out of 5 on our list. It is classed as Ester / Fatty Acids & Derivatives.
Sources we checked this rating against
- Kligman AM, Kwong T. “An improved rabbit ear model for assessing comedogenic substances.” British Journal of Dermatology, June 1979;100(6):699–702. (opens in a new tab) The rabbit-ear assay behind published 0 to 5 comedogenicity grades.
- Fulton JE Jr. “Comedogenicity and irritancy of commonly used ingredients in skin care products.” Journal of the Society of Cosmetic Chemists, November/December 1989;40(6):321–333. (opens in a new tab) Rabbit ear. Each ingredient at 10 percent in propylene glycol unless stated, applied five days a week for two weeks, and graded 0 to 5 from the width of the follicles, measured by micrometer and under the microscope. The paper counts 0 to 1 as not significant, 2 to 3 as borderline and 4 to 5 as positive. Some grades depended on the supplier of the raw material, and some oils were also tested refined.
- Morris WE, Kwan SC. “Use of the rabbit ear model in evaluating the comedogenic potential of cosmetic ingredients.” Journal of the Society of Cosmetic Chemists, August 1983;34(5):215–225. (opens in a new tab) Rabbit ear canal, at the Revlon Research Center. Each material applied undiluted unless stated, once a day five days a week for 14 applications, and graded 0 to 5 by microscope only. The authors set out to recheck earlier results because investigators disagreed.
- Ahn HY, Myung KB, Hahm JH, Kook HI. “An experimental study on comedogenicity of several external contactants.” Korean Journal of Dermatology, October 1985;23(5):620–629. (opens in a new tab) Rabbit ear canal; in the abstract’s words, the materials were applied to one ear canal of rabbits "for 6 weekdays for 2 weeks". Read at abstract level: the full text is not online. The abstract sorts ingredients into none, mild, moderate and severe with no 0 to 5 grade, and lists propylene glycol under both none and moderate. Kligman 1996 says that putting test materials inside the ear canal gave false positives in his own 1972 study, because loose horny material collects in the follicles there.
- Draelos ZD, DiNardo JC. “A re-evaluation of the comedogenicity concept.” Journal of the American Academy of Dermatology, March 2006;54(3):507–512. doi:10.1016/j.jaad.2005.11.1058 (opens in a new tab) Tested finished products on the backs of six people and concluded that “Finished products using comedogenic ingredients are not necessarily comedogenic.”