Lanolin or petroleum jelly: which is better for skin and balms?

Lanolin tested positive in 1.64% of 30,629 patch test patients, petrolatum in 0.03%. FDA sets them at 12.5-50% and 30-100%. The 400% water claim, traced.

Petroleum jelly is the safer default and the stronger seal; lanolin is the better choice only when you need its tack, its water uptake or an animal-derived, non-fossil ingredient, and you know the user does not react to it. The numbers behind that are specific. In a 25 year series of 30,629 patch-tested patients in north-eastern Italy, 1.64 percent reacted to the lanolin marker; in 79,365 patients of a German-based network tested with pure white petrolatum, 0.03 percent gave a positive reaction, and the authors considered many of those irritation. The US over-the-counter monograph accepts lanolin as a skin protectant at 12.5 to 50 percent and petrolatum at 30 to 100 percent. And the "holds 400 percent of its weight in water" line on the first page of search results has no primary source this site could find: the measured figure is 180 percent.

• Lanolin positive: 1.64% of 30,629
• Petrolatum positive: 0.03% of 79,365
• FDA lanolin 12.5-50%
• FDA petrolatum 30-100%
• Water uptake measured: 180%
• 400% claim: no primary source found

The two materials, measured side by side

Every row below comes from a document anyone can open: the FDA's skin protectant list at 21 CFR 347.10; two large patch test analyses, Cegolon and Larese Filon's 2024 study of the Triveneto database in Italy and Schnuch and colleagues' 2006 analysis of the German-based Information Network of Departments of Dermatology (IVDK); the Cosmetic Ingredient Review's 2024 lanolin assessment; a 1978 Woolcombers patent by E. W. Clark that measured water uptake before and after purifying lanolin; and Sethi and colleagues' 2016 review of moisturisers.

Two rows decide most choices: the allergy row and the occlusion row, and petroleum jelly wins both. What lanolin has instead is harder to put in a table: a tacky, cushioned film that stays where it is put, and the ability to hold water in the product itself. The fuller material notes are on the lanolin and petrolatum and mineral oil ingredient pages.

The 400 percent figure, traced to its sources

The lanolin sellers who fill the first page of results for this comparison repeat one number above all others: lanolin "holds 400 percent of its weight in water", sometimes "up to 400 percent". None of the pages we read cites a measurement for it. Here is every figure for lanolin's water uptake that a primary or regulatory-grade source actually states.

So the verdict is plain: the documented figure for ordinary anhydrous lanolin is about twice its weight, 180 percent in the one measured case, and the highest number in any source here, 300 percent, belongs to lanolin that has been purified and then had a fatty alcohol added back to boost its emulsifying power. That is a modified product, not the lanolin in a tub. We could not find a primary source for 400 percent. A figure nobody can trace to a measurement should not be quoted.

The number probably persists because it sounds like a benefit to skin, and it is not one. Water uptake is a property of the product in the jar: it is how much water lanolin can hold as a water-in-oil mixture before the water separates out. It says nothing about drawing water into skin, and an anhydrous balm has no water in it to hold. The property matters for formulators making creams and ointments, and it has a second use covered on the cold water swimming balm page, where lanolin's willingness to take up water keeps the film tacky when wet. For a balm on dry skin, the relevant question is how well the film stops water leaving, which is the job described in occlusive, emollient and humectant.

Why the water uptake and the allergy come from the same fraction

The Clark patent is worth reading for more than its numbers, because it shows the trade that every lanolin buyer is making without being told. The patent reports analyses of "more than 30 different samples of lanolin" that found free fatty alcohols, the alcohols not bound up in esters, "always present in amounts varying from 5% to 12.6%". When they were stripped out completely, "the resultant lanolin esters had negligible emulsifying power". The free alcohols are what let lanolin hold water.

They are also where the allergy lives. The patent reports patch tests on people "known to be hypersensitive to ordinary lanolin" with four versions of the material, and the share who reacted fell as each contaminant was removed:

The patent's worked examples report the same direction at two hospitals: after the free alcohols were cut from 8.7 to 2.2 percent and the detergent to under 0.01 percent, allergy among previously reactive patients fell "from 89.47% to 5% at one hospital and from 23% to zero at a second". Its own threshold for "substantially hypoallergenic" lanolin is free fatty alcohols reduced "to approximately 3.0% or less", with detergent under 0.05 percent.

Put the two findings together and the trade is clear. Removing the free alcohols brought water uptake down from 180 percent to between 130 and 155 percent in Clark's examples, and removing them together with detergent residues brought reactions in sensitised patients close to zero. The lanolin with the least allergy risk is also the lanolin that holds the least water. A product marketed as both "hypoallergenic" or "ultra-pure" and "holds 400 percent of its weight in water" is claiming both ends of a trade that the underlying chemistry makes you choose between. The detail of today's grades and what "medical grade" means is on the lanolin allergy guide.

Allergy: 1.64 percent against 0.03 percent

This is the section competitor pages leave out, and it is the one that decides most choices. Cegolon and Larese Filon analysed 30,629 consecutive patients patch tested in north-eastern Italy from 1997 to 2021, all tested with lanolin alcohol at 30 percent in petrolatum, the European baseline marker since 1969. The study abstract gives the patient count as 30,269, but the methods, results and the rate's own denominator (501 of 30,629) all give 30,629, so the abstract's figure is a transposition. 501 patients reacted: 1.64 percent.

For petrolatum, the Schnuch analysis of IVDK data covered 79,365 patients patch tested with pure petrolatum between 1992 and 2004. It found 27 '+' reactions (0.03 percent) and 2 '+++' reactions (0.003 percent). The authors judged that "many of the '+' reactions have to be considered as irritant", found that one of the two strong reactions was an "angry back" reaction and the other "probably a reading or documentation error", and concluded that "true allergic patch test reactions to white petrolatum are extremely rare". Their title puts it more briefly: "virtually non-sensitizing".

Three readings follow. First, in comparable clinic populations, lanolin positives run at roughly fifty times the petrolatum figure, and many of the petrolatum positives were judged irritation rather than allergy. Second, the lanolin rate depends heavily on the test material. Amerchol L-101, which Cegolon describes as "a mixture of 10% lanolin alcohols and mineral oil", picks up more positives than lanolin alcohol 30 percent, and some authors suspect part of the difference is false positives from irritation. The North American rate more than doubled when the test material changed in 2011. Third, these are clinic figures. Everyone in them was referred because a doctor suspected contact allergy, so they overstate what happens in the general public, a point the lanolin allergy guide works through with population data.

One detail links the two materials directly. Every lanolin test in the table is lanolin alcohol or Amerchol dispersed "in pet.", in petrolatum. Petrolatum is the vehicle in patch test preparations, so clinics depend on it not reacting on its own, and Schnuch's 79,365 patients show that it almost never does.

Who actually reacts to lanolin

The Italian series is useful beyond its headline rate because it reports where on the body patients' dermatitis was and which groups reacted more. The pattern points at how lanolin sensitisation happens.

The authors' reading is that leg dermatitis in older patients often comes from stasis dermatitis or leg ulcers, "conditions recommending topical application of emollients", so the risk group is people who have spread lanolin-containing products on broken, inflamed skin for months or years. The studies they review point the same way: in an IVDK series from 1996 to 1999, the lanolin rate was 3.1 percent at 60 or under, 8.3 percent at 61 to 65 and 12.5 percent over 75. The CIR reaches the same conclusion from its own review: "Allergic reactions are observed primarily in patients with stasis dermatitis, leg ulcers, perianal/genital dermatitis, and atopic dermatitis." It adds that children and the elderly carry a greater risk "due to comorbidities". Atopic dermatitis is on the CIR list even though the Italian series found no association, one more sign that the answer depends on the test material and the population.

The Italian rate also fell over time, "especially after 2003", and Cegolon cites a small study in which a lanolin cream applied repeatedly to 12 patients who had tested strongly positive to Amerchol L-101 "failed to induce any positive reaction". Together they say that a positive patch test does not always mean a reaction to a lanolin product in use, and that the risk sits with damaged skin and long exposure. For a healthy lip, a lanolin balm is a low-risk product; for a leg ulcer or eczema that has been treated for years, petroleum jelly is the more cautious base. How to test a new balm on yourself first is set out in how to patch test a balm.

Occlusion: what the 98 percent figure means

The number that fills petroleum jelly pages is "reduces water loss by 98 percent". Sethi and colleagues' review states it in full: "Petrolatum in a minimum concentration of 5% reduces TEWL by more than 98% followed by lanolin, mineral oil, and silicones which only reduce TEWL by 20–30%." TEWL is transepidermal water loss, the water that escapes through the skin's surface. The same review says petroleum jelly has "a water vapor loss resistance 170 times that of olive oil".

Two limits come with that sentence. The review cites earlier work for it, a 2001 Skin Therapy Letter article by Lynde and a 1971 paper by Spruit in Dermatologica, and gives no method, dose or skin site, so the two percentages are not a controlled head-to-head test that anyone can check from the review. And "20 to 30 percent" for lanolin sits awkwardly with lanolin's reputation, and with this site's own qualitative ranking of lanolin as very highly occlusive among natural materials. What the sources support is the ranking, not the gap: petrolatum is the strongest occlusive in routine use, and lanolin is less occlusive. We found no open-access study measuring both under the same conditions, so this page does not put a single number on the difference.

The practical reading: if the problem is water leaving the skin, petroleum jelly does that job better than anything else a balm maker is likely to use. Lanolin's case rests on its tacky film that stays put on lips and nipples through movement, the reason given on the ingredients for chapped lips page, and not on sealing better.

Concentration: what the US monograph sets for each

In the United States, a product that claims to protect skin is an over-the-counter drug, and 21 CFR 347.10 lists the active ingredients that may carry that claim, each "within the concentration specified". Lanolin's band is 12.5 to 50 percent. Petrolatum and white petrolatum are each 30 to 100 percent. The same list gives mineral oil 50 to 100 percent (30 to 35 percent only in combination with colloidal oatmeal), cocoa butter 50 to 100 percent and dimethicone 1 to 30 percent. Section 347.3 defines a lip protectant as a product that "temporarily prevents dryness and helps relieve chapping of the exposed surfaces of the lips; traditionally called 'lip balm'".

The asymmetry is the useful part. Lanolin has a ceiling: above 50 percent it no longer qualifies as a monograph active. Petrolatum has a floor and no ceiling: plain petroleum jelly is itself a compliant skin protectant. Section 347.20(a) lets lanolin and petrolatum be combined, "provided each ingredient in the combination is within the concentration specified". The labelled uses permitted include "temporarily protects" and "helps relieve" "chapped or cracked skin" or, for a lip protectant, "chapped or cracked lips", and the required warnings include "Stop use and ask a doctor if condition worsens" and, for the cuts and chapped skin uses, "Do not use on deep or puncture wounds, animal bites, serious burns".

Most small makers do not want a drug product at all, and the way to stay a cosmetic is to make no protectant claim, whatever the lanolin level. Where the line falls is set out in cosmetic against drug claims, and a worked example that stops just short of the lanolin band on purpose is the winter face barrier balm. The same bands are applied to a petrolatum base in the ointment base formula.

Outside the monograph, the CIR's 2022 industry survey found lanolin used "in lipsticks at up to 20.7%" and "up to 40% in leave-on nail creams and lotions", levels the panel judged "safe in cosmetics in the present practices of use and concentration". A lip product at 15 to 20 percent lanolin sits inside normal practice.

Which to choose for which product

For nipple care, the worked formula is nipple balm, and for heels, foot and heel balm. For nappy care, the regulatory picture above is applied directly on nappy rash balm.

Sourcing is the one real reason many buyers prefer lanolin, and it is a values choice, not a skin one: nothing in the allergy or occlusion data favours lanolin. The case against petrolatum is about fossil origin and refining quality, and the refining question, including what pharmacopoeial grade guarantees, is worked through in is petroleum jelly bad for you and natural against petroleum.

What these numbers do not settle

The allergy comparison joins two clinic networks, in different countries and partly different decades: Italian patients from 1997 to 2021 for lanolin, IVDK patients from 1992 to 2004 for petrolatum. Both groups were referred for suspected contact allergy, so the fiftyfold ratio is an order of magnitude, not a precise multiple, and neither study tested finished products in everyday use.

The water uptake figures come from one 1978 patent and a descriptive line in the CIR report. Clark does not describe his method, and modern grades may differ from 1970s lanolin, but the direction of the trade is clear: removing free alcohols cuts both water uptake and allergy.

The occlusion figures are the weakest part of the evidence. The ranking, petrolatum above lanolin, is consistent; the size of the gap rests on one sentence in a review with no conditions stated. Finally, the monograph bands are US law only. A balm sold in the EU or UK is judged under those markets' own cosmetic rules, which include a safety assessment, whatever its lanolin or petrolatum level.

Reviewed and updated 30 September 2026. Spotted an error? Tell us and we will fix and log it.