Stretch Marks: Causes and Treatment

Stretch marks are permanent scars in the dermis caused by skin stretching beyond its elastic capacity. Whether they improve significantly with treatment depends primarily on how old they are: red or purple stretch marks (striae rubra) respond reasonably well to several treatment approaches; white or silver stretch marks (striae alba) are among the more resistant skin concerns in non-surgical aesthetics. Understanding which you have determines what is realistically achievable.

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What stretch marks are

The clinical term is striae distensae, more commonly divided into striae rubra (early) and striae alba (mature). They are not a surface condition; they are scars in the dermis, the structural layer of the skin where collagen and elastin fibres provide tensile strength.

When skin is stretched faster than the dermis can adapt, collagen and elastin fibres rupture. The initial response is inflammatory: blood vessels in the area dilate and the skin appears red or purple. This is the striae rubra phase. Over months to years, the inflammation resolves, the blood vessels contract, and the ruptured collagen is replaced by scar tissue. The skin in the area loses pigment and becomes white, silver or pale: striae alba.

The two phases respond very differently to treatment, and being clear about which phase a patient is in is the starting point for any realistic conversation about what treatment can achieve.

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What causes them

Stretch marks develop when the rate of skin stretching exceeds the rate at which the dermis can remodel its collagen. Several situations reliably produce this:

Pregnancy. The abdomen, breasts, hips and thighs are the most common sites. The combination of rapid skin stretching and hormonal changes during pregnancy, particularly elevated cortisol and oestrogen, alters collagen synthesis in a way that makes the dermis more vulnerable to tearing.

Adolescent growth. Rapid growth in height during puberty produces stretch marks on the thighs, hips, lower back and in some cases the upper arms. These often develop in teenagers who have no other risk factors and are a normal part of development.

Rapid weight gain or loss. Significant and rapid change in body weight stretches the skin faster than it can adapt during weight gain, and leaves excess skin with altered structural integrity after rapid loss.

Bodybuilding and rapid muscle gain. The upper arms, shoulders and pectorals are common sites in patients who have achieved rapid muscle growth. The skin stretches over developing muscle faster than collagen can accommodate.

Corticosteroid use. Both topical (applied to skin) and systemic corticosteroids suppress collagen synthesis and thin the dermis, making it more susceptible to tearing with much less stretch than would otherwise be required. Patients on long-term corticosteroid therapy or who apply strong topical steroids to large areas over extended periods may develop striae without obvious mechanical cause.

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Red versus white stretch marks: why it matters for treatment

	Striae rubra	Striae alba
Appearance	Red, pink or purple; may be raised initially	White, silver or pale; flush with or slightly depressed below skin surface
Stage	Early: inflammation still active, blood vessels dilated	Mature: inflammation resolved, scar tissue established
Collagen status	Ruptured but healing process partially ongoing	Scar tissue has replaced normal collagen
Pigment	Retained or overactive (inflammatory pigment)	Lost: melanocytes in the area have reduced activity
Response to treatment	Reasonable: inflammation and vascular component can be targeted; collagen stimulation during active phase is effective	Limited: established scar tissue with absent pigment is resistant to most treatments; texture improvement is achievable but colour normalisation is not

This distinction is the single most clinically important thing to communicate to patients presenting with stretch marks. The reasonable improvement achievable in striae rubra does not translate to striae alba, and patients who see treatment results for the early phase and extrapolate to white stretch marks are likely to be disappointed.

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Treatment options

What helps striae rubra

Laser treatment (Nd:YAG). The vascular component of red stretch marks can be targeted with the Nd:YAG 1064nm wavelength available on the Cynosure Elite+ laser at The London Road Clinic. Targeting the dilated blood vessels beneath the red colour reduces the inflammatory redness and can flatten raised stretch marks. This is most effective in the early inflammatory phase and less so once the marks have begun to lighten.

Microneedling. Collagen induction via microneedling is well-supported for striae rubra. The wound-healing response from controlled micro-injury stimulates new collagen formation in a site where the collagen architecture is damaged but the repair response is still active. Over a course of four to six sessions, texture, width and colour improvement is achievable. The microneedling patient guide covers the mechanism and treatment detail.

Fractora RF microneedling. For more pronounced or widespread striae rubra, Fractora’s combined mechanical and thermal stimulus produces stronger collagen remodelling than standard microneedling alone. Recovery of three to seven days per session should be planned. See the Fractora patient guide.

Topical retinoids. Retinoids have published evidence for reducing the length, width and colour of striae rubra when applied consistently over several months. They do not produce dramatic visible improvement on their own, but as an adjunct to in-clinic treatment or as a maintenance strategy, consistent retinoid application to affected areas is one of the few topical approaches with a genuine evidence base.

Chemical peels. Superficial to medium-depth chemical peels improve the surface quality of the skin over stretch marks and can contribute to texture improvement in striae rubra. They address the surface component; collagen induction treatments address the structural deficit below.

What helps striae alba

Honest expectation-setting is the most important part of the conversation about white stretch marks. No current non-surgical treatment reliably restores the colour of mature, white stretch marks to match surrounding skin. Melanocytes in the affected area have reduced activity and do not reliably respond to the treatments that stimulate melanin production in other contexts.

What is achievable with striae alba:

• Texture improvement. Microneedling and Fractora can reduce the textural difference between the stretch mark and the surrounding skin. The scar tissue can be partially remodelled, producing marks that are narrower, smoother and less pronounced in feel.
• Width reduction. Over multiple sessions, the lateral extent of white stretch marks can reduce meaningfully.
• Visual prominence. Improved texture and reduced width make the marks less visually prominent even where the colour difference remains.

What is not reliably achievable:

• Colour restoration. White stretch marks do not consistently return to the surrounding skin tone with any treatment currently available in aesthetic practice.
• Complete removal. Stretch marks are dermis-level scars; no non-surgical treatment removes them.

Surgical options (excision for abdominal stretch marks within an abdominoplasty, for example) exist but are outside the scope of aesthetic non-surgical treatment. Patients with significant structural skin excess alongside stretch marks who want a more complete result should discuss surgical assessment with an appropriate specialist.

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What does not help

Oils and creams marketed to prevent or remove stretch marks. No topical product, however well-formulated, reaches the dermis in concentrations sufficient to affect established scar tissue. Oils (coconut, rosehip, bio-oil) keep the skin moisturised and may slightly improve surface texture, but they do not prevent striae from forming and do not reverse them once established. The evidence base for popular stretch mark creams is consistently weak. Money spent on retinoids and SPF delivers more measurable benefit than money spent on products marketed specifically for stretch marks.

One treatment session. Stretch marks are dermis-level scarring. One session of any treatment produces modest improvement at best. A course of treatment over several months, with realistic expectations established at the outset, is what produces meaningful improvement.

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Prevention: what actually makes a difference

Prevention is not fully possible for stretch marks driven by pregnancy or adolescent growth, because the rate of stretching exceeds what preventive measures can fully offset. But several factors reduce the risk or severity:

• Keeping skin well-hydrated and moisturised during periods of rapid change maintains the epidermis and may reduce the degree of tearing in the dermis, though evidence is limited.
• Gradual weight and muscle gain rather than rapid change reduces the mechanical stress on the dermis.
• Avoiding unnecessary long-term topical corticosteroid use on skin areas vulnerable to stretch marks.
• SPF on affected areas exposed to UV. UV exposure makes established stretch marks more visually prominent because the surrounding skin tans and the scar tissue does not. Consistent SPF on areas with stretch marks reduces this contrast effect over summer months. See the sun damage and SPF guide.

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When to see your GP

Most stretch marks are a normal consequence of life events and do not require medical investigation. However:

• Wide, deep purple stretch marks across the abdomen, flanks and thighs that develop without obvious mechanical cause may indicate elevated cortisol levels (Cushing’s syndrome). If accompanied by weight gain concentrated around the abdomen, fatigue, or other systemic symptoms, a GP review with blood tests is appropriate before aesthetic treatment is considered.
• Stretch marks in children or young teenagers that are very widespread or accompanied by unusual symptoms warrant GP assessment to exclude endocrine causes.
• Skin that tears very easily with minimal stretching may reflect a connective tissue disorder worth investigating.

In the absence of these flags, stretch marks are a cosmetic concern that an aesthetic clinic is the appropriate first point of contact for.

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