Anti-ageing treatments that work: what the evidence says

The anti-ageing treatments that work best are also the least glamorous: a broad-spectrum sunscreen used every day and a topical retinoid such as tretinoin. Both have randomised controlled trials behind them, which is more than most products on the shelf can say.

Below that top level sit ingredients with moderate evidence, such as vitamin C, niacinamide and alpha hydroxy acids. Further down are products with limited or mixed evidence, including most peptide creams and collagen drinks. In-clinic procedures can add a lot, but they are a separate decision made in person with a doctor.

This guide sorts the main options into evidence levels so you can spend your effort, and money, where the research is strongest.

Key takeaways

- Daily sunscreen is the best-proven way to slow visible skin ageing: in one 4.5-year trial, skin ageing was 24% less with daily use than with occasional use [1].

- Tretinoin is the most studied topical for fine wrinkles, mottled pigmentation and roughness. It is prescription-only and not used in pregnancy [3][4].

- Vitamin C, niacinamide and glycolic or lactic acid show modest benefits in smaller studies [6][7][8].

- Collagen supplements, most peptides and "stem cell" creams have limited or inconsistent evidence [9][10].

- Expect gradual change over months, not a different face in weeks.

Why skin ages: time versus the sun

Skin ages in two overlapping ways. Intrinsic ageing is driven by genes and time: skin becomes thinner, drier and slowly loses elasticity.

Photoageing is the extra damage from years of ultraviolet (UV) exposure. It shows up as fine and coarse wrinkles, rough texture, sallowness and uneven pigmentation, including the sun spots discussed in our guide to dark spots on the face.

This distinction matters because most of the visible change on the face, neck and backs of the hands is linked to the sun. That is why the two best-supported strategies are preventing further UV damage and repairing some of the damage already done.

Level 1, strong evidence: daily sunscreen

The clearest trial comes from Nambour, Australia. Researchers randomly assigned 903 adults under 55 to apply a broad-spectrum sunscreen every day or to keep using sunscreen as and when they chose [1].

After 4.5 years, the daily sunscreen group showed no detectable increase in skin ageing. Overall, skin ageing from baseline was 24% less in the daily group than in the discretionary group [1]. The same trial found that beta-carotene supplements had no overall effect on skin ageing [1].

The study had limits: some outcome data were missing and its power to detect moderate effects was modest [1]. Even so, it is one of the few long-term randomised trials of any anti-ageing measure.

What this means in practice:

• Apply a broad-spectrum sunscreen to the face, neck and hands every morning, not only on holidays.
• Use enough to cover the skin evenly and reapply when you are outdoors for long periods.
• Add shade, hats and sunglasses on high-UV days.
• Sunscreen also supports every other treatment in this guide, because retinoids and acids make skin more sensitive to the sun.

Level 1, strong evidence: topical retinoids

Retinoids are vitamin A derivatives. Tretinoin (retinoic acid) is the one with the longest track record for photoageing.

Tretinoin

In a 16-week double-blind trial, 14 of 15 people who applied tretinoin to the face improved, compared with none of those using the vehicle cream [2]. A larger 24-week multicentre trial of 296 people with photodamaged skin found that 68% of those using tretinoin 0.05% improved, against 43% with vehicle [3]. An "excellent or good" response was seen in 26% versus 11% [3].

Those numbers are worth reading carefully. Tretinoin helped clearly more people than vehicle, but most did not see a dramatic transformation, and the lowest concentrations tested did no better than vehicle [3]. The improvements were in fine wrinkling, mottled pigmentation and roughness, not deep folds.

In Spain, tretinoin cream is a prescription-only medicine. Its product information lists it as an adjunct treatment for fine wrinkles, mottled hyperpigmentation and roughness of facial skin caused by chronic sun exposure, used alongside sun avoidance and sunscreen [4]. You can read more in our tretinoin anti-ageing guide and the beginner's guide to tretinoin.

Retinol

Retinol is a weaker, over-the-counter relative. In a 24-week trial in 36 older adults (mean age 87), 0.4% retinol improved fine wrinkling on the arm compared with vehicle [5]. It is a reasonable option for people who want something gentler, although direct comparisons with tretinoin are scarce. Our article on adapalene vs tretinoin vs retinol explains the differences.

Safety: pregnancy, irritation and sun

• Pregnancy and breastfeeding: tretinoin is contraindicated in pregnancy and in women planning a pregnancy, and in breastfeeding it is used only if the benefit justifies the possible risk [4]. If you are pregnant or trying to conceive, ask a doctor before using any retinoid, including retinol.
• Irritation: redness, peeling and burning are the most common side effects, usually mild to moderate [3]. Doctors often build the use up gradually, and the prescribing doctor sets the strength and how often to apply it.
• Sun sensitivity: the product information asks users to avoid the sun and use sunscreen during treatment [4].

Hi Doctor offers topical skin treatments only. A doctor reviews your case and decides whether tretinoin is appropriate for you, at what strength, and how to start it.

Level 2, moderate evidence: vitamin C, niacinamide and acids

These ingredients have some controlled trials behind them, but the studies are smaller, shorter or more often funded by manufacturers.

Topical vitamin C

A 2023 systematic review found seven publications with 139 volunteers in total [6]. Treated skin appeared smoother and less wrinkled, and pigmentation lightened, but the authors noted that long-term use may be needed and that more studies are required to confirm the effect and the ideal concentration [6]. Vitamin C serums can also oxidise, so storage matters.

Niacinamide

In a 12-week split-face trial, 50 women applied 5% niacinamide to one side of the face and vehicle to the other [7]. The niacinamide side showed reductions in fine lines, hyperpigmented spots, red blotchiness and sallowness [7]. The study was run by researchers from a consumer-products company, which is worth keeping in mind. Niacinamide is usually well tolerated.

Alpha hydroxy acids (glycolic and lactic acid)

A 22-week trial in 74 women aged 40 to 70 compared 8% glycolic acid, 8% lactic acid and a vehicle cream [8]. At least one grade of improvement in overall facial photodamage was seen in 76% with glycolic acid, 71% with lactic acid and 40% with vehicle [8]. The authors described the effect as modest [8]. Acids can sting or irritate, especially when combined with a retinoid.

Level 3, limited evidence: peptides, collagen and "stem cell" creams

A 2021 systematic review of over-the-counter anti-ageing ingredients concluded that, despite the huge choice on the market, good evidence supporting their use is often lacking [9]. Several popular options fall into this level.

• Collagen supplements and drinks: a 2025 meta-analysis of 23 randomised trials with 1,474 participants found an overall benefit for hydration, elasticity and wrinkles. However, studies without industry funding, and the high-quality studies, showed no significant effect, and the authors concluded there is currently no clinical evidence to support collagen supplements for skin ageing [10].
• Most peptide creams: many have laboratory data or small manufacturer studies, but independent long-term trials are limited [9].
• Plant "stem cell" and growth-factor creams: evidence is limited, and laboratory findings do not show what happens on a real face over months.

Limited evidence does not mean these products are harmful. It means you cannot count on them, and they should not replace sunscreen or a retinoid.

Evidence levels at a glance

Option	Evidence level	What studies show	Main cautions
Daily broad-spectrum sunscreen	Strong	24% less skin ageing over 4.5 years vs occasional use [1]	Needs daily, generous use
Tretinoin (prescription)	Strong	68% improved vs 43% with vehicle at 24 weeks [3]	Irritation, sun sensitivity, not in pregnancy [4]
Retinol (over the counter)	Moderate to strong	Fine wrinkles improved vs vehicle in older adults [5]	Milder irritation; ask before use in pregnancy
Topical vitamin C	Moderate	Smoother, less wrinkled skin in small trials [6]	Small studies; product stability
Niacinamide 5%	Moderate	Fewer fine lines and spots in a 12-week split-face trial [7]	Mostly industry-run studies
Glycolic or lactic acid 8%	Moderate	76% and 71% improved vs 40% with vehicle [8]	Stinging, irritation
Collagen supplements	Limited	No effect in independent or high-quality trials [10]	Cost without proven benefit
Peptides, stem-cell creams	Limited	Data mostly small or laboratory-based [9]	Marketing often exceeds data

Realistic expectations

Topical treatments work slowly. The tretinoin and acid trials above ran for 16 to 24 weeks [2][3][8], and benefits on fine lines, texture and pigmentation are usually gradual. Deep wrinkles, volume loss and sagging respond little to creams. Stopping sunscreen or a retinoid generally means losing ground again, so think of them as long-term habits.

Procedures done in person by a doctor

For changes that creams cannot reach, there are in-clinic procedures. All of them require an in-person assessment, ideally by a dermatologist or a doctor trained in aesthetic medicine.

• Chemical peels: controlled application of acids to remove damaged surface layers. Deeper peels give more change but more downtime and risk of pigment changes.
• Lasers and light-based devices: used for wrinkles, texture, redness and sun spots. The right device depends on skin type and goal.
• Botulinum toxin injections: relax the muscles behind expression lines such as frown lines. The effect wears off after some months.
• Dermal fillers: usually hyaluronic acid gels to restore volume or soften folds. They carry injection-related risks and need an experienced injector.
• Microneedling: a 2025 systematic review of 21 studies with 723 patients found 83% patient satisfaction and mostly transient side effects such as redness, but noted a lack of standardised outcome measures [11].

Hi Doctor does not perform or arrange any of these procedures. If you are considering one, ask about the practitioner's training, the expected number of sessions and the realistic result for your skin.

When to see a doctor

Ageing skin is not a medical problem in itself, but some changes need an in-person check. See a doctor or dermatologist promptly if you notice:

• A new mole, or a mole that changes in size, shape or colour, bleeds or itches.
• A sore, scaly patch or bump that does not heal within a few weeks.
• A dark spot that looks different from your other spots, grows quickly or has irregular edges.
• Brown patches on the cheeks, forehead or upper lip, which may be melasma and need a specific approach (see our melasma page).
• Severe redness, swelling or blistering after starting a retinoid or acid.

For an overview of the topical options doctors use for photoageing, see the anti-ageing dermatology page.

Sources

1. Hughes MC, Williams GM, Baker P, Green AC. Sunscreen and prevention of skin aging: a randomized trial. Ann Intern Med. 2013;158(11):781-790. DOI: 10.7326/0003-4819-158-11-201306040-00002. https://pubmed.ncbi.nlm.nih.gov/23732711/
2. Weiss JS, Ellis CN, Headington JT, Tincoff T, Hamilton TA, Voorhees JJ. Topical tretinoin improves photoaged skin. A double-blind vehicle-controlled study. JAMA. 1988;259(4):527-532. https://pubmed.ncbi.nlm.nih.gov/3336176/
3. Olsen EA, Katz HI, Levine N, et al. Tretinoin emollient cream: a new therapy for photodamaged skin. J Am Acad Dermatol. 1992;26(2 Pt 1):215-224. DOI: 10.1016/0190-9622(92)70030-j. https://pubmed.ncbi.nlm.nih.gov/1552056/
4. AEMPS, CIMA. Ficha técnica: tretinoína 0,5 mg/g crema (n.º de registro 60141). Medicamento sujeto a prescripción médica. https://cima.aemps.es/cima/dochtml/ft/60141/FT_60141.html
5. Kafi R, Kwak HS, Schumacher WE, et al. Improvement of naturally aged skin with vitamin A (retinol). Arch Dermatol. 2007;143(5):606-612. DOI: 10.1001/archderm.143.5.606. https://pubmed.ncbi.nlm.nih.gov/17515510/
6. Correia G, Magina S. Efficacy of topical vitamin C in melasma and photoaging: a systematic review. J Cosmet Dermatol. 2023;22(7):1938-1945. DOI: 10.1111/jocd.15748. https://pubmed.ncbi.nlm.nih.gov/37128827/
7. Bissett DL, Oblong JE, Berge CA. Niacinamide: a B vitamin that improves aging facial skin appearance. Dermatol Surg. 2005;31(7 Pt 2):860-865. DOI: 10.1111/j.1524-4725.2005.31732. https://pubmed.ncbi.nlm.nih.gov/16029679/
8. Stiller MJ, Bartolone J, Stern R, et al. Topical 8% glycolic acid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlled clinical trial. Arch Dermatol. 1996;132(6):631-636. https://pubmed.ncbi.nlm.nih.gov/8651713/
9. Imhof L, Leuthard D. Topical over-the-counter antiaging agents: an update and systematic review. Dermatology. 2021;237(2):217-229. DOI: 10.1159/000509296. https://pubmed.ncbi.nlm.nih.gov/32882685/
10. Myung SK, Park Y. Effects of collagen supplements on skin aging: a systematic review and meta-analysis of randomized controlled trials. Am J Med. 2025;138(9):1264-1277. DOI: 10.1016/j.amjmed.2025.04.034. https://pubmed.ncbi.nlm.nih.gov/40324552/
11. Foppiani JA, Fanning JE, Beltran K, et al. Microneedling for facial rejuvenation: a systematic review. Aesthetic Plast Surg. 2025;49(17):4949-4960. DOI: 10.1007/s00266-025-04972-z. https://pubmed.ncbi.nlm.nih.gov/40542236/