First part
In this second part we will start examining the natural mummies. You probably know that the most famous red-haired mummies are those found in desertic environments, but I’ve decided to begin this article with the bog bodies. Many think the chemistry behind the red hair of the bog bodies is well known, but this is not the case. What we will see in this paragraph will be useful in the next article as well, where we will talk about the desertic mummies.
Bog bodies
The so-called bog bodies are naturally mummified bodies (or skeletons) found in peat bogs, which are usually distributed in cold, temperate climes, mostly in boreal ecosystems in the Northern Hemisphere (we have mentioned them in this article). The anaerobic environment and presence of tannic acids within bogs can result in the remarkable preservation of organic material. Furthermore, the high levels of acidity often darken the skin of these bodies and turn their hair a vibrant red, although not all bog bodies have red hair. There is even a “bog dog” found in Lower Saxony (Germany) and its fur too turned reddish.
As a matter of fact, we still don’t know the chemical process that causes some of these mummies to have red hair. The explanation usually given (here’s an example) is that the dark pigment eumelanin, being less stable than the yellow-red phaeomelanin, degrades over the millennia, so the remaining phaeomelanin gives hair a reddish colour. However, there is no evidence of that.
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| Osterby Man |
Eumelanin vs Phaeomelanin
The problem is that speaking of this or that melanin being more stable or resistant than the other doesn’t make any sense, because it all depends on the context where the melanin is, so to speak. Besides, not only melanins are made up of several elements (that’s why they are considered polymers, or biopolymers), but the two are also very different the one from the other (see, for instance, A Comparative Study of the Physical and Chemical Properties of Melanins Isolated from Human Black and Red Hair).
Apparently, the idea of eumelanin being less stable comes from the 1987 study Chemical- and photo-bleaching of brown and red hair (by Wolfram & Albrecht) which, however, is not about peat bogs or mummies. It studies hair bleaching with hydrogen peroxide and sunlight, and the authors conclude that, under those conditions, phaeomelanin is more resistant to bleaching than eumelanin.
Subsequently, archaeologists extended this observation to peat bog mummies and mummies in general. However, since the original experimental evidence does not concern peat bogs, but rather cosmetic bleaching and photodamage, transferring that result to a peat bog environment (acidic, anoxic, rich in humic acids and poor in oxidizing radicals) is a plausible hypothesis, but not a proof.
In following studies eumelanin proved to be more stable tnat phaeomelanin.
For example, as we will see in the next paragraph, under UV radiations phaeomelanin is less photo-stable and degrades more quickly that eumelanin.
The 2005 study by Yan Liu and colleagues Comparison of Structural and Chemical Properties of Black and Red Human Hair Melanosomes shows that eumelanin is more resistant to chemical and mechanical manipulations.
The study Sediment-encased pressure–temperature maturation experiments elucidate the impact of diagenesis on melanin-based fossil color and its paleobiological implications shows that, during the maturation of modern feathers in conditions simulating fossilisation, eumelanin is more stable than phaeomelanin, so much so that dark colours are preserved better than reddish ones. Of course, a peat bog isn't a fossil deposit subjected to high pressure and temperature, so that result can't be automatically transferred. However, it does demonstrate that the relative stability of the two pigments depends greatly on the chemical environment, and that there's no universal rule that phaeomelanin would always be the more resistant.
The 2016 review Fifty Shades of Black and Red or How Carboxyl Groups Fine Tune Eumelanin and Pheomelanin Properties summarises the knowledge accumulated over the past years on the chemistry of melanins and explains that the properties of eumelanin and phaeomelanin are much more variable than previously thought. Authors explain that both melanins are families of polymers and that small structural differences profoundly alter their properties. "Eumelanin" does not exist as a single material: its stability depends on its chemical composition, so comparing "eumelanin" and "phaeomelanin" as if they were two pure substances is an oversimplification.
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| Bocksten Man |
Possible scenarios
I have not studied all the bog bodies (here’s the list), but in a least two cases the original hair colour was found out. Osterby Man was described as dark blond, while Yde Girl was described as blond.
Now, in blond hair there are very small amounts of eumelanin and phaeomelanin, so, if all eumelanin should degrade, the remaining phaeomelanin wouldn’t be enough to colour the hair a vibrant red.
Besides, if palaeochemists managed to identify the original hair colour of these two bodies, it means that both melanins were still there, at least in part.
The logical conclusion is that the red colour we see in bog bodies is not caused by eumelanin degradation, but by other processes, that could be:
- chemical alteration of eumelanin without complete destruction, with a change in its optical properties;
- alteration of keratin, which changes the way light is scattered by the hair;
- adsorption of humic substances or iron complexes on the hair surface;
- a combination of these phenomena.
An often overlooked factor is that hair is an optical as well as a pigmentary material. Colour depends not only on the amount of melanin, but also on how light passes through the cortex, is absorbed by melanosomes, and scatters by keratin. If the microstructure changes over decades or centuries, the perceived colour can change even without a massive loss of pigment.
Besides, since not all bog bodies show red hair, probably this reddening also depends on several more factors, such as how long the body remains in peat, the chemical composition of the bog, the temperature, the amount of iron in peat, pH levels and, probably, the individual’s natural hair colour.
A very curious thing is that one of the humic substances of peat bogs is called fulvic acid, because of its reddish brown colour (fulvus in Latin means tawny or reddish yellow).
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| Fulvic acid isolated from peat |
Is there a way to clarify the matter?
Oddly enough, no studies have recreated an "artificial peat bog" in the laboratory specifically to observe the colour changes in human hair. Such an experiment would be relatively simple to design and, I assume, not too expensive. Furthermore, it would not be necessary to take hair samples from the mummies.
As we have seen in the previous article, archaeologists are often more interested in diet, DNA, causes of death and overall preservation, and original hair colour has been considered a secondary issue. Besides, well-preserved bog bodies are few and museums tend to limit destructive hair samplings.
In any case, since bogs are more common in the Northern Emisphere, some of the mummies may well have natural red hair.
(As for the darkening of these mummies’ skin, the process seems to be clearer. Basically, thanks to the tannic acids, the skin undergoes a sort of tanning like in the tanning of leather. Here are a couple of articles on the subject: 1 and 2).
Photo-oxidation
Photo-oxidation is sometimes brought up to explain the red hair of certain mummies.
Photo-oxidation is the degradation of a polymer surface (and we have seen that melanin is a polymer) due to the combined action of light and oxygen. Today, it is the most significant factor in the weathering of plastics.
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| On the left, a rope which has been degraded by weathering. On the right, a fresh rope |
Through this process, when hair is exposed to sunlight, the ensuing chemical reaction leads to various structural and aesthetic changes in hair fibers.
As far as colour is concerned, photo-oxidation can alter the pigmentation of hair, leading to fading or discoloration. This is particularly noticeable in dyed or bleached hair, which may lose its vibrancy over time. Prolonged exposure to UV radiation can also weaken the hair, resulting in a loss of elasticity. This makes hair more prone to breakage and split ends.
The whole process involves the interaction of UV light with the hair's chemical components, primarily keratin and melanin. This interaction can degrade melanin, causing lighter or altered shades. Furthermore, as free radicals increase and keratin is also damaged, the hair becomes more porous and appears "discolored".
Photo-oxidation is a phenomenon you can observe on yourself as well: if you spend a lot of time in the sunlight, especially in the summer, you hair can become lighter. I remember that one summer I would often dry my hair under the sun and at the end of the summer it had lightened so much that even my hairdresser noticed.
There are several laboratory experiments on photo-oxidation (I will link some of them below) but none of them shows that hair can become red as a result of photo-oxidation. According to the amounts of eumelanin and phaeomelanin, hair can get reddish or copper shades, or it can become browninsh, warm brown, browninsh with reddish shades. but it will never become red as in a person with natural red hair.
The 2009 review Photoaggravation of Hair Aging, citing previous works, argues (as we mentioned in the previous paragraph) that eumelanin has got a higher photostability than phaeomelanin and it is more resistant to UV radiations. This is the reason why blond and especially red hair lighten more quickly than dark hair.
A very important point to understand is that no study has ever demonstrated that a colour can change to the point of entering another colour class, that is, becoming another colour. Even when hair colour lightens, it doesn't become another colour.
For example, in the 2004 study Hair color changes and protein damage caused by ultraviolet radiation (Nogueira and Joekes) the authors proved that UVA radiations lighen hair colours, especially blond and above all red, but they didn’t observe an extreme colour change. The reason is that photo-oxidation gradually degrades melanin, but does not completely eliminate it, as can be achieved by bleaching with high-concentration peroxide. Furthermore, as melanin degrades, keratin damage increases, so the hair tends to reach a sort of plateau: it continues to deteriorate structurally, but the colour does not continue to lighten indefinitely. This trend is consistent with experimental studies on photobleaching (at the bottom of the article I’ve linked more experiments like this one).
In the forensic field, these changes in hair colour are a well-known aspect, but what’s the problem with mummies? The problem is that (as you can easily understand), if a body remains under the sun for such a long time that its hair undergoes a visibile colour change, eventually that body will be destroyed by weather, wild animals and bacteria and will never become a mummy, let alone a well-preserved mummy like the ones we know.
As a matter of fact, photo-oxidation was mentioned to explain the red colour of the hair of one of the Gebelein predynastic mummies, the one called EA 32751 and kept in the British Museum. This mummy was formely known as Ginger, but then, after the Human Tissue Act 2004, the British Museum has developed policies for ethical treatment of human remains, and no longer uses this nickname. They clearly think that a code name such as EA 32751 is less “offensive” than Ginger. 😁 These mummies are naturally mummified bodies found in Upper Egypt and dating back to about 3000 BC.
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| Ginger and his red hair |
Now, something curious happened with the Wikipedia page about the Gebelein mummies. Here’s the previous Wikipedia page (from June 2026) and, as you can see, at the end of the first section there are two paragraphs about Ginger’s hair colour. Photo-oxidation is mentioned to explain the red colour, but then they add “there is no evidence to suggest that the Gebelein mummies were subjected to years of prolonged sunlight following their burial.” Dr Janet Davey (see previous article) is also mentioned, along with her experiment with natron and her conclusion that “a minority of ancient Egyptians could have had naturally fair or reddish hair.” However, these two paragraphs are no longer present on the current page and no possible explanation is given for Ginger’s red hair. If you check the history of this article on Archive, you’ll see that these paragraphs about Ginger’s hair colour first appeared on the 5th September 2025, so they only stayed online for less than a year.
Since I am on this subject, I want to add something that has nothing to do with mummies. Photo-oxidation is sometimes brought up to explain the red hair seen on natives by early explorers of Polynesia (we talked about it here). According to this explanation, those explorers did not see natural red hair, but dark or brown hair with reddish shades caused by prolonged photo-oxidation. It may be, although I find it strange that all those explorers couldn’t tell the difference between natural red hair and dark/brown hair with reddish shades. As a matter of fact, if you read their reports, they seem quite good at distinguishing different nuances of colours. Besides, some of the natives they met also had fair skin.
Some studies on photo-oxidation
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