Inherency and obviousness are two well-known and well-recognized U.S. patent law doctrines with fundamental differences. Inherency is a fact issue, requiring a showing that the feature or limitation at issue is either necessarily present in, or the natural result of, the elements explicitly disclosed by the prior art. Obviousness, on the other hand, is a matter of law based on findings of underlying facts. The obviousness analysis examines the knowledge of a person of ordinary skill in the art at the relevant time.  

Because inherency focuses on what was disclosed in the prior art, analyzing whether a claim limitation is inherent can involve looking back, for example by examining prior art features, to determine if a claim limitation was inherently disclosed. In contrast, the obviousness analysis forbids hindsight, focusing only on what a person of ordinary skill in the art would have recognized on the relevant critical date.1

It is, therefore, possible for a claim limitation to inherently exist in a prior art reference, even though a person of ordinary skill in the art would not have recognized it at the time of invention.

Early case law taught that inherency did not usually have a role to play in an obviousness analysis since "the inherency of an advantage and its obviousness are entirely different questions. That which may be inherent is not necessarily known. Obviousness cannot be predicated on what is unknown." In re Shetty, 566 F.2d 81, 86 (C.C.P.A. 1977). But more recently, courts have considered inherency arguments when analyzing obviousness, focusing on the unexpectedness of the asserted inherent features. Honeywell Int'l Inc. v. Mexichem Amanco Holding S.A. de C.V., 865 F.3d 1348, 1355 (Fed. Cir. 2017) ("What is important regarding properties that may be inherent, but unknown, is whether they are unexpected."). This is a cautious consideration:

We have recognized that inherency may supply a missing claim limitation in an obviousness analysis. We have, however, also explained that the use of inherency, a doctrine originally rooted in anticipation, must be carefully circumscribed in the context of obviousness. . . . A party must, therefore, meet a high standard in order to rely on inherency to establish the existence of a claim limitation in the prior art in an obviousness analysis[.] (citations omitted).

Par Pharm., Inc. v. TWi Pharms., Inc., 773 F.3d 1186, 1194-96 (Fed. Cir. 2014) (emphasis added); see also Millennium Pharms., Inc. v. Sandoz, Inc., 862 F.3d 1356, 1367 (Fed. Cir. 2017).


In L'Oréal USA, Inc. v. Olaplex, Inc., 2021 U.S. App. LEXIS 2457, -- F. App'x. --- (Fed. Cir. Jan. 28, 2021) (unpublished), the Federal Circuit affirmed the Patent Trial and Appeal Board's (Board) determination that certain claims of Olaplex U.S. Patent No. 9,668,954 ("the '954 patent") were unpatentable as obvious.2 The Court also affirmed the Board's determination that another group of claims (called "the breakage claims") of the '954 patent were not unpatentable. According to the Court, the breakage-decrease requirements of this latter set of claims limited the scope of the invention. The Federal Circuit agreed with the Board that L'Oréal failed to establish that the breakage claims' limitations were inherent in the prior art.


L'Oréal USA, Inc. (L'Oréal) filed a petition for post-grant review (PGR) of all claims of the '954 patent. See PGR2018-00025. The '954 patent, then owned by Liqwd, Inc., claims methods of treating hair using, among other things, maleic acid. This method purportedly rebuilds the disulfide bonds in keratin found in hair, which can be damaged during bleaching. '954 patent, col. 7, lines 16-17, 42-46. Liqwd transferred its interest in the '954 patent to Olaplex, Inc. while the appeal was pending; the Federal Circuit allowed the substitution of parties.

In its Final Written Decision, the Board determined that claims 1-13, 19-23, and 29-30 were unpatentable for obviousness based on the combination of U.S. Patent Publication No. 2012/0024309 (Pratt) and U.S. Patent No. 6,359,502 (Tanabe).

Claim 1 of the '954 patent, in the group of claims found unpatentable, recites:

  1. A method for bleaching hair comprising:
    (a) mixing a bleach powder and a developer to form a bleaching formulation;
    (b) mixing an active agent formulation comprising an active agent with the bleaching formulation to form a mixture, wherein the active agent is maleic acid; and
    (c) applying the mixture to the hair;
    wherein the active agent in the mixture is a concentration ranging from about 0.1 % by weight to about 50% by weight.

Claims 14-16, 18, and 24-28, the "breakage claims," each found to be not unpatentable, add a limitation: hair breakage must decrease by a certain level.  For example, claim 24 recites:

  1. The method of claim 1, wherein following step (c) breakage of the hair is decreased by at least 5% compared to hair bleached with the bleaching formulation in the absence of the active agent.

Prior Art

The Board addressed several combinations of prior art references. On appeal, the Federal Circuit focused on one: the combination of Pratt and Tanabe.

Pratt: U.S. 2012/0024309, titled "Bleaching/Highlighting Composition."
Pratt disclosed a composition for bleaching hair comprising three parts: (1) "a substantially anhydrous composition comprising at least one compound with bleaching effect"; (2) "an aqueous composition comprising at least one oxidizing agent"; and (3) "a composition comprising at least one cationic and/or cationizable compound." L'Oréal, 2021 U.S. App. LEXIS 2457, at *6-7. Pratt further explained that the third composition "preferably comprises additionally at least one hair conditioning compound" and that the pH is "most preferably" between 3 and 6, and "in particular" between 3 and 5. Id. at *7. In one embodiment, Pratt disclosed that "maleic acid" is used to "adjust" the pH of the composition, and that the preferred mixing ratio of the three parts of the overall composition is "4:4:0.2 to 4:4:0.75." Id.

Tanabe: U.S. 6,359,502, titled "Hair Cosmetic Compositions Containing Glycine and Alanine."
Tanabe disclosed a cosmetic composition of at least three components: (1) "glycine or alanine"; (2) an acid; and (3) "a cationic surfactant." Id. at *8. For the acid, Tanabe describes "maleic acid" as one of three "particularly preferred." Id. Tanabe also teaches that the composition's pH "may range" from 2 to 6, but a pH from "2.5 to 3.5" is "particularly preferred." Id.


Motivation to Combine
The Board found, and the Federal Circuit agreed, that a relevant artisan would have had reason to combine Pratt and Tanabe to carry out the claimed process recited in the group of claims it found to be unpatentable. The Federal Circuit noted that there were no differences between the combined teachings of Pratt and Tanabe and the claimed invention. Id. at *19.

For example, when Tanabe's conditioner with maleic acid was used as the "third composition" of Pratt's mixture and method, all the limitations of claim 1 were met, the Court held. Id. at *10. The Federal Circuit noted that the Board's conclusion was supported by L'Oréal's expert, Dr. Wickett, who stated that a person of ordinary skill in the art would have understood that Tanabe's compositions would function as Pratt's third composition, providing conditioning benefits for the hair. Id. at *11 and *20. And the Court noted that the Board reasonably found that it was well-known in the art to add conditioners to bleaching mixtures to counteract bleach damage. Id. Further, the concentration-range limitations of the '954 patent were similarly taught by Pratt and Tanabe, the Court noted. Id. at *10. 

In sum, the Federal Circuit held, the Board reasonably determined that L'Oréal had shown a motivation to combine, rendering the challenged claims obvious.

Reasonable Expectation of Success
The Federal Circuit similarly agreed with the Board's finding that there was a "substantial overlap" in ingredients for Tanabe and Pratt's compositions, and thus that a skilled artisan would have understood that Tanabe's compositions are suitable for use as Pratt's third composition. Id.  

Olaplex could not sufficiently show, the Federal Circuit held, that the Board's finding on reasonable expectation of success was unsupported by the record. Rather, considering all the relevant factors, the Board's finding that a relevant artisan would have had a reasonable expectation of success in combining Tanabe and Pratt was supported by substantial evidence, the Court held. Id. at*24.

Objective Evidence
Olaplex presented evidence of indicia of nonobviousness, which was focused largely on alleged copying in the industry. The Board gave this evidence little weight. The Federal Circuit agreed, holding that the Board made sufficient nexus findings, and no other objective indicia sufficiently suggested nonobviousness.


The Board found that while the combination of the teachings of Pratt and Tanabe would reduce hair breakage, L'Oréal had not shown that it was "necessarily so for any or all of the breakage claims." Id. at *39. For example, L'Oréal did not show that the combination of Pratt and Tanabe would meet the specifically claimed breakage decreases with respect to "every formulation meeting the broad claim 1 concentration range" of the '954 patent, the Board found. Id. at *40.

The Federal Circuit affirmed these findings, holding that L'Oréal did not prove that the breakage-decrease percentages in the breakage claims were necessarily present in, or the natural result of, the combined teachings of the prior art. Id.

Takeaway Lessons

This decision is unpublished and may not be cited as precedent.  Nonetheless, it illustrates the Federal Circuit's approach to inherency.  Inherency is a narrow doctrine, the Court warns.  It must be "carefully circumscribed" in obviousness analyses, so that it does not lead to improperly discounting unexpected results or justifying hindsight obviousness arguments.


1. Under the America Invents Act (AIA, 35 USC § 1 et seq.), this date is the effective filing date.  Under pre-AIA law, this date is the purported date of invention.

2. While the validity of the '954 patent and its related patent, U.S. 9,498,419 (the '419 patent) was being separately reviewed before the Board, Liqwd and Olaplex filed suit in the U.S. District Court for the District of Delaware, alleging that L'Oréal's products infringed certain claims of the '954 and '419 patents. The district court granted Liqwd and Olaplex's motion for summary judgment of direct and indirect infringement on all claims and issued a permanent injunction.
L'Oréal appealed to the Federal Circuit. Following Board proceedings, among the asserted claims only three asserted claims-claims 14-16 of the '954 patent-survived. The Federal Circuit concluded that there were genuine questions of material fact relating to infringement of claims 14-16 of the '954 patent and vacated and remanded the case to the district court for trial. L'Oréal USA, Inc. v. Olaplex, Inc., Case Nos. 2019-2280, 2292 (Mar. 4, 2021) (non-precedential).

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