Do We Age in Bursts? What the 44 and 60 Studies Mean for Your Face, and What to Do at Each

Last updated: 8 November 2026

In short: Probably, yes. Two large molecular studies have found that the body does not age at a steady pace but in waves, with the sharpest changes clustering around the mid forties and around sixty, in men as well as women. The findings are about molecules in blood, not wrinkles, and the studies have real limits, but they fit what I see in clinic and what the skin research has shown for decades: faces tend to change in steps, after long plateaus. That has practical consequences for when to protect, when to assess and when to treat.

Almost everyone who sits down in my consultation room in Hale says a version of the same thing: "I looked the same for years and then, in about eighteen months, everything changed." Patients in their mid forties say it. Patients around sixty say it. For a long time medicine treated this as a trick of perception, on the grounds that ageing is a slow, steady slope and people simply stop noticing until something tips them into noticing. Recent research suggests the patients were right and the slope was wrong.

This article looks at the evidence that we age in bursts rather than in a straight line, what the two most cited studies actually measured and how much weight they can bear, why the face in particular seems to change in steps, and what, if anything, you should do differently at the ages the data points to.

In this article:

• Do we age in bursts? What the Stanford study found
• The earlier evidence: three waves in the blood
• How much can these studies tell us? The caveats
• Why the face in particular ages in steps
• The two ages that matter most for your face, and what happens at each
• What to do at the mid forties checkpoint
• What to do at the sixty checkpoint
• Does this mean the years in between do not matter?
• What happens at my clinic in Hale
• Frequently asked questions

Do we age in bursts? What the Stanford study found

In August 2024 a team at Stanford led by Professor Michael Snyder published a study in the journal Nature Aging that followed 108 adults aged 25 to 75 for several years, taking regular blood, stool, skin, nasal and oral samples and measuring more than 135,000 different molecules and microbes in them, nearly 250 billion data points in all. The question was simple: do these molecules change steadily with age, or not?

They did not. For most of the molecules measured, levels stayed fairly stable for years and then shifted sharply, and the shifts clustered at two ages.

Burst	What changed	Why it is interesting
Around 44	Molecules involved in metabolising alcohol, caffeine and fats; markers linked to cardiovascular disease; and pathways related to skin and muscle	The team expected this to be the menopause showing up in the women. It appeared in the men too, so something else is driving it
Around 60	Carbohydrate metabolism, immune regulation, kidney function and a further shift in cardiovascular markers; skin and muscle pathways again	Matches the age at which many chronic diseases become more common, and at which many people describe a second step change in how they look and feel
In between	Relative stability; most molecules changed little from year to year	The plateaus are as much a finding as the peaks, and they explain the "nothing, nothing, then everything" that patients describe

"We're not just changing gradually over time; there are some really dramatic changes." Professor Michael Snyder, Stanford Medicine, senior author of Nonlinear dynamics of multi-omics profiles during human aging, Nature Aging, 2024.

The detail that matters most for this article is a small one: skin and muscle pathways were among those that shifted at both 44 and 60. The study did not photograph faces or measure wrinkles, but the molecular machinery that maintains skin was changing at exactly the ages my patients point to.

The earlier evidence: three waves in the blood

The Stanford paper was not the first to find waves. In 2019 a different Stanford group, led by Tony Wyss-Coray, published a study in Nature Medicine of nearly 3,000 proteins in the blood of more than 4,000 people aged 18 to 95. Protein levels did not drift steadily with age; they changed in three waves, peaking at around 34, 60 and 78. Roughly a third of all the proteins measured changed markedly across the lifespan, and the pattern was undulating rather than linear.

Study	What was measured	Ages of accelerated change
Lehallier and colleagues, Nature Medicine, 2019	Nearly 3,000 blood proteins in more than 4,000 people aged 18 to 95, measured once each	34, 60 and 78
Shen and colleagues, Nature Aging, 2024	More than 135,000 molecules and microbes in 108 people aged 25 to 75, sampled repeatedly over several years	44 and 60
Where they agree	Different people, different methods, different decades of research	Both find ageing is nonlinear, and both find a burst at around 60

The two studies disagree on the earlier wave, 34 in one and 44 in the other, which is a reminder that the exact ages are less important than the shape. Two independent groups using different methods both found that the body ages in steps, and both found one of those steps at around sixty.

How much can these studies tell us? The caveats

As a GP I would not be doing my job if I passed these findings on without their limits, which the authors themselves are careful about.

Caveat	Why it matters	What it means for you
108 people is not many	The 2024 study is deep (hundreds of thousands of measurements per person) but narrow; the exact ages could shift in a larger group	Treat "44" and "60" as regions, not birthdays
Molecules are not wrinkles	Neither study measured skin thickness, collagen or how old a face looked; the link from a blood protein to a jowl is plausible, not proven	The studies explain a pattern; they do not diagnose your face
Behaviour may drive some of it	The authors note that mid forties changes in alcohol and caffeine metabolism could partly reflect a stressful decade of drinking more, sleeping less and exercising less, rather than pure biology	Some of the "burst" may be yours to influence
Mostly cross sectional	The 2019 study compared different people of different ages at one moment; the 2024 study followed people over a few years but not through a whole burst	Nobody has yet watched one person's molecules through their forties and sixties from start to finish
Not everyone has the same timetable	Genetics, sun, smoking, sleep, weight change and, for women, the timing of the menopause move the steps earlier or later	Your face, not your age, is what gets assessed

With those limits in mind, the findings still earn their place, because they agree with something the skin literature has shown for forty years without anyone calling it a burst.

Why the face in particular ages in steps

Long before anyone measured 135,000 molecules, dermatologists had found that the skin does not age smoothly. Skin collagen declines by about one per cent a year through adult life, and then, in women, by up to 30 per cent in the five years after the menopause before settling to a slower rate. That is a step by any definition, and it lands squarely in the first burst for women. The facial skeleton also changes in a non uniform way, with the eye sockets widening and the upper jaw receding at rates that accelerate in later life, and the mid face fat compartments shift and thin in a pattern that CT studies show is concentrated in particular decades rather than spread evenly.

On top of the biology, the face has a property that makes steps inevitable even if the underlying decline were smooth: thresholds.

Threshold	What is slowly changing underneath	What suddenly appears
A line stops springing back	Collagen and elastin thin by a fraction each year beneath a crease that forms thousands of times a day	One year the frown line is there in the morning when your face is at rest; it looks as though it arrived overnight
A cheek stops holding up a fold	The deep cheek fat thins steadily and the bone beneath recedes	The nose to mouth fold deepens and a shadow appears under the eye, within the same year
Skin stops fitting the frame	The skeleton shrinks a little, the fat redistributes, and the skin loses elasticity, all slowly	Jowls and a softer jawline arrive together, because all three crossed their limits in the same window
A trigger removes the margin	Years of reserve were masking the loss	The menopause, rapid weight loss, a bereavement, a bad year of sleep, or a bout of illness takes the last of the margin and the face changes in months

So the face would look as though it aged in steps even if the body did not, and the body, it turns out, does too. The two effects stack, which is why the mid forties and around sixty are the two moments when patients most often tell me they no longer recognise themselves.

The two ages that matter most for your face, and what happens at each

What changes	The mid forties burst	The sixty burst
Skin	Lines at rest for the first time; duller, drier, more reactive skin; in women, the start of the menopause collagen cliff	Noticeably thinner, crepey skin, especially neck, chest and hands; slower healing; more sun damage surfacing as pigment and texture
Fat and structure	Cheeks begin to flatten; nose to mouth folds deepen; the first sense of a heavier lower face	Temples hollow, jowls and a softer jawline are established, the eye area looks more skeletal as the socket widens
Muscle	Muscle pathways shift in the molecular data; the start of sarcopenia for people who do not train	Visible loss of muscle in the face and neck contributes to hollowing; strength matters more than ever
Metabolism	Alcohol and caffeine are processed more slowly; the same glass of wine shows more in the face the next morning	Carbohydrate metabolism shifts; blood sugar control and its skin consequences, including glycation, become more relevant
What people say	"I suddenly look tired all the time"	"I look like my mother"

What to do at the mid forties checkpoint

If the body is going to change in a burst, the useful response is to arrive at the burst in good order and to reassess on the far side of it, rather than to panic in the middle. For the mid forties that means three things.

Priority	What to do	Why now
Protect the collagen you still have	Daily SPF, a prescription retinoid, and a serious look at alcohol, sleep and smoking	The burst takes a percentage of what is there; the more there is, the more remains. Alcohol metabolism slows in exactly this window, so the same intake costs more
Start building, not just preserving	Resistance exercise for muscle; collagen stimulating treatments such as polynucleotides or microneedling for skin quality; for women, the menopause conversation with your GP before symptoms force it	Muscle and skin pathways both shift here; banking collagen before the cliff is cheaper than rebuilding after it. See collagen banking explained
Get a baseline, then wait	Standardised photographs and an assessment of structure around 44 or 45; hold off major structural treatment until the face has settled on the other side	Treating a face that is mid burst is like decorating a room mid renovation; the baseline tells you later what actually changed

What I would not do in the mid forties is reach for volume. The flattening cheek and deepening fold at 45 are early, the structure is mostly intact, and filler added now is the volume women most often regret at 55. Skin quality and prevention in the mid forties; structure, if needed, in the fifties. For the fuller picture of this decade see why your face changes in your forties.

What to do at the sixty checkpoint

Priority	What to do	Why now
Health first, and it shows	The NHS Health Check if you have not had one, blood pressure, blood sugar and cholesterol with your GP; protein and strength training	The sixty burst is about carbohydrate metabolism, immunity, kidneys and heart as much as skin; the face reflects all of them
Rebuild support where it has gone	Sculptra for diffuse mid face and temple loss; Radiesse for jawline structure; hyperdilute Radiesse for neck and hands	By sixty structure, not skin, is usually the dominant change, and biostimulators rebuild it with your own collagen rather than adding weight
Treat the skin that drapes over it	Polynucleotides, a retinoid your skin can tolerate, SPF without exception; a peel for sun damage once the barrier is stable	Structure without skin quality looks firm but old; thinner skin at sixty needs gentler, more consistent care
Be realistic about the frame	Where there is marked skin excess, a plain conversation about surgery; injectables improve, they do not lift	The best results at this age come from knowing what each tool can and cannot do; see you are not too old for aesthetic treatments

Does this mean the years in between do not matter?

No, and this is the misreading I most want to head off. The plateaus between bursts are when the reserve is built or spent. A face that arrives at 44 with twenty years of daily sunscreen, a decade of retinoid and no cigarettes has more collagen for the burst to take a percentage of, and crosses its thresholds later and more gently. A face that arrives at 60 with a well maintained mid face and a strong neck has less structure to lose. The bursts decide when the change shows. The plateaus decide how much there is to show.

Phase	The job	The mistake
Plateau (late twenties to early forties)	Build reserve: SPF, retinoid, no smoking, sleep, strength; small conservative treatments for movement lines if wanted	Doing nothing because nothing is visibly wrong, or adding volume to a face that has not lost any
Burst (mid forties)	Protect and build skin quality; baseline photographs; the menopause conversation; patience with structure	Panic treatment of every new line with filler, mid change
Plateau (fifties)	Rebuild what the first burst took: collagen first, then structure, with the face now settled enough to plan properly	Treating only the skin surface when the change is structural, or the reverse
Burst (around sixty)	Health, strength, support, skin quality, realism	Assuming it is too late, or expecting injectables to do a face lift's job

What happens at my clinic in Hale

Step	What happens
Consultation	Around 45 minutes with me, £75 redeemable against treatment. Where you are relative to these changes, what has altered and over what period, what is still moving; skin, movement, dermis and structure assessed; standardised photographs as a baseline
The plan	Matched to the phase you are in: build reserve, protect through a burst, or rebuild afterwards; written in order with timings and prices, and with "wait and photograph again in six months" as a legitimate recommendation
The GP part	Where the changes point to something medical, the menopause, blood sugar, blood pressure, sleep or alcohol, I say so and point you to your own GP; the clinic treats the face, not the condition
Who you see	Me, every time; I am the only practitioner at the clinic

Patients come to the clinic from Hale, Altrincham, Bowdon, Hale Barns, Timperley, Sale, Wilmslow, Alderley Edge, Knutsford and Didsbury, and the two commonest ages on my consultation list are, unsurprisingly, the mid forties and around sixty. Arriving a year or two before the burst, with a baseline and a plan, is the quiet advantage the research offers.

Takeaway: The body appears to age in waves rather than a straight line, with bursts of molecular change around the mid forties and sixty, and the face, which works on thresholds, changes in steps for reasons of its own. The two effects stack, which is why so many people feel they aged overnight at 45 or 60. Build reserve in the plateaus, protect and photograph through the bursts, rebuild afterwards, and treat the face in front of you rather than the age on the form.

Frequently asked questions about ageing in bursts

Do humans really age in bursts rather than gradually?

The best current evidence says yes. A 2024 Stanford study of more than 135,000 molecules in 108 people found that most changed little for years and then shifted sharply at around 44 and 60. An earlier study of blood proteins in more than 4,000 people found waves at 34, 60 and 78. Both are about molecules rather than appearance, and both have limits, but both find steps, not a slope.

At what ages do you age the fastest?

According to the 2024 study, the mid forties and around sixty. The 2019 protein study found peaks at 34, 60 and 78. The exact ages vary between studies and between people; the agreement is on the shape and on a burst around sixty.

Why do I look older suddenly at 45?

Three things coincide. The body's molecular ageing accelerates in the mid forties, including pathways that maintain skin and muscle. For women, the menopause collagen cliff often begins. And the face works on thresholds: years of slow collagen and fat loss cross the point where a line stays at rest or a cheek stops holding up a fold, so changes that were decades in the making become visible in months.

Is the mid forties burst just the menopause?

No. The Stanford researchers expected it to be and found the same changes in men. For women the menopause adds its own, steeper, collagen loss on top of the shared burst, which is one reason women often notice the mid forties change more sharply than men do.

Why do I suddenly look like my mother at 60?

Because the second burst falls on structure. By sixty the facial skeleton has receded, the deep fat has thinned and shifted, and the skin is thinner and less elastic; the sixty burst in metabolism, immunity and muscle coincides with those thresholds being crossed. Family resemblance shows most when the underlying frame is what is on display.

Can you slow or prevent an ageing burst?

You can change how much it has to take. Daily SPF, a retinoid, not smoking, sleep, strength training and moderate alcohol build the reserve that a burst then takes a percentage of. The authors of the 2024 study also note that some of the mid forties change in alcohol and caffeine metabolism may reflect behaviour, which is within your control.

Should I have aesthetic treatments before or after a burst?

Protect and build skin quality before and during, with SPF, a retinoid and collagen stimulating treatments such as polynucleotides or microneedling. Rebuild structure after, once the face has settled, with Sculptra, Radiesse or carefully placed filler as needed. Treating structure in the middle of a change means treating a face that will not exist in a year.

What is the best age to start anti ageing treatment?

Prevention starts in the twenties with sunscreen. Skin quality treatment makes sense from the late thirties or early forties. Structural treatment makes sense when structure has been lost, which for most people is the fifties. The research on bursts supports getting a baseline assessment in the early to mid forties, before the first big change.

Does everyone age at 44 and 60?

No. These are averages from relatively small studies. Genetics, sun exposure, smoking, weight change, illness and the timing of the menopause move the steps earlier or later, and some people change more gradually. The consultation assesses your face, not your date of birth.

Are these studies reliable?

They are good studies with clear limits: the 2024 one followed only 108 people, neither measured appearance directly, the earlier one compared different people at one moment rather than following individuals, and behaviour may explain part of the pattern. They should be read as a plausible explanation for something patients have described for years, not as a timetable.

Next steps

If you are approaching your mid forties or sixty, or feel you have just come through a change you did not see coming, book a consultation at the clinic in Hale. We will take a baseline, work out which phase your face is in and what is still moving, and build a plan that fits it, including, where it is the right answer, waiting.

Learn more about Dr Caroline Warden Clinic

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Learn more about other treatments offered

Further reading

• The Best Aesthetic Treatments for Your 30s, 40s, 50s and Beyond
• Why Your Face Changes in Your 40s and What Actually Helps
• Why Some Women Feel They Have Aged Overnight
• Does Menopause Make You Look Older?
• Why Collagen Declines and the Treatments That Actually Stimulate It
• Has My Face Fallen? Cheek Filler, Sculptra and Radiesse Compared
• Polynucleotides in Hale and Altrincham (for skin quality before and during a burst)
• Sculptra in Hale and Altrincham (for rebuilding structure afterwards)

Dr Caroline Warden (GMC 6157708) is an NHS GP with over 19 years of clinical experience, an independent prescriber, and holds a Level 7 postgraduate diploma in cosmetic injectables. She has practised aesthetic medicine since 2017 and is the sole practitioner at Dr Caroline Warden Skin & Aesthetic Clinic, which she runs with her sister Louise at 2 Crown Passages, Hale, Cheshire, WA15 9GN, serving patients from Hale, Altrincham, Bowdon, Hale Barns, Timperley, Sale, Alderley Edge, Wilmslow, Knutsford, Didsbury and across Cheshire and South Manchester. The clinic was named Best Doctor Led Aesthetic Clinic in Cheshire 2026 by GHP. The clinic is an authorised Obagi stockist and sells skincare products; this is a commercial interest and is declared here. The clinic does not diagnose or treat medical conditions; blood pressure, blood sugar, the menopause and other health matters raised in this article are for your own GP, and prescription only medicines are prescribed following a face to face consultation and are not promoted here. This article provides general educational information and does not replace an individual consultation.

References

1. Shen X, Wang C, Zhou X, et al. Nonlinear dynamics of multi-omics profiles during human aging. Nature Aging 2024;4: pages 1619 to 1634. Read the study
2. Stanford Medicine. Stanford Medicine researchers find that aging is not linear, with bursts of change around 44 and 60. News release, August 2024, reported by Longevity Technology. Read the report
3. Lehallier B, Gate D, Schaum N, et al. Undulating changes in human plasma proteome profiles across the lifespan. Nature Medicine 2019;25(12): pages 1843 to 1850. Read the abstract
4. National Institutes of Health. Blood protein signatures change across lifespan. NIH Research Matters, December 2019. Read the summary
5. Brincat M, Kabalan S, Studd JW, et al. A study of the decrease of skin collagen content, skin thickness, and bone mass in the postmenopausal woman. Obstetrics and Gynecology 1987;70(6): pages 840 to 845. Read the abstract
6. Shuster S, Black MM, McVitie E. The influence of age and sex on skin thickness, skin collagen and density. British Journal of Dermatology 1975;93(6): pages 639 to 643. Read the abstract
7. Gierloff M, Stöhring C, Buder T, et al. Aging changes of the midfacial fat compartments: a computed tomographic study. Plastic and Reconstructive Surgery 2012;129(1): pages 263 to 273. Read the abstract
8. Mendelson B, Wong CH. Changes in the facial skeleton with aging: implications and clinical applications in facial rejuvenation. Aesthetic Plastic Surgery 2012;36(4): pages 753 to 760. Read the abstract