Niacinamide has several properties that could theoretically improve stretch marks, but there is no published clinical evidence proving it works for this specific concern. No peer-reviewed study has tested topical niacinamide on stretch marks and measured the results. That said, the ingredient does meaningful things for skin that overlap with what stretch marks need to heal, which is why it shows up in so many body care products marketed for this purpose.
What Stretch Marks Actually Need to Improve
Stretch marks form when the dermis, the thick middle layer of your skin, tears under rapid stretching from growth spurts, pregnancy, weight changes, or muscle gain. The collagen and elastin fibers that normally keep skin flexible break apart, leaving visible lines that start out red or purple and eventually fade to white or silver.
For any ingredient to meaningfully improve stretch marks, it needs to do several things: boost collagen production, increase skin elasticity, reduce inflammation (especially in newer marks), and support healthy cell turnover. A 2016 review in the Journal of the European Academy of Dermatology and Venereology noted that no single topical treatment has become a gold standard for stretch marks, and most available products lack strong clinical evidence. That’s the honest backdrop for evaluating niacinamide or any other ingredient for this use.
How Niacinamide Affects Skin Biology
Niacinamide, a form of vitamin B3, is one of the more well-studied skincare ingredients overall, even if stretch mark research specifically is missing. It works as a precursor to a molecule called NAD+, which is essential for energy production, DNA repair, and stress responses in skin cells. This gives it a broad range of effects rather than one narrow function.
Its anti-inflammatory action is well documented. Niacinamide activates an enzyme involved in both reducing inflammatory signals and repairing DNA damage. For newer, red stretch marks where inflammation and blood vessel dilation cause that visible redness, this property is relevant. Newer stretch marks also tend to itch, and calming inflammation can help with that symptom too.
One of niacinamide’s most concrete effects is on the skin’s protective barrier. Lab research found that niacinamide increased ceramide production by 4 to 5.5 times compared to untreated cells. It also boosted free fatty acid levels by 2.3 times and cholesterol synthesis by 1.5 times. These lipids form the “mortar” between your skin cells, keeping moisture in and irritants out. When applied topically, niacinamide raised ceramide and fatty acid levels in the outermost layer of skin and reduced water loss. A stronger barrier means skin that’s more resilient, better hydrated, and potentially better equipped to handle stretching without tearing further.
There’s also evidence that niacinamide reduces glycation, a process where sugars cross-link with collagen proteins and make them stiff and brittle. Preventing this keeps existing collagen more flexible. And one niacinamide-derived molecule (NIA-114) has been shown to stimulate the production of type I and type IV collagen, the main structural proteins in skin. But again, this collagen-boosting effect hasn’t been tested in stretch mark tissue specifically.
Newer Red Marks vs. Older White Marks
Stretch marks go through two distinct phases, and the distinction matters for choosing treatments. Red or purple stretch marks (called striae rubrae) are newer. They still have active blood flow, inflammation, and some remaining structural integrity in the dermis. This is the window when topical treatments of any kind tend to have the most impact, because the tissue is still actively remodeling.
White or silver stretch marks (striae albae) are mature scars. The inflammation has resolved, pigment-producing cells in the area have become inactive, and the collagen has reorganized into scar tissue. These marks need an increase in pigmentation and a rebuilding of dermal structure, which is a much harder ask for any topical product.
Niacinamide’s anti-inflammatory and redness-reducing properties line up well with the needs of newer stretch marks. For older, white marks, its barrier-strengthening and collagen-supporting effects could help improve texture and hydration in the area, but dramatic visible changes are unlikely from niacinamide alone.
What Concentration to Look For
Most clinical research on niacinamide’s skin benefits uses concentrations between 5% and 10%. Products in the 2% to 5% range provide barrier support and gentle anti-inflammatory effects, while 5% to 10% is considered the range where you get the full spectrum of benefits without irritation. Body skin is generally thicker and less sensitive than facial skin, so products at the higher end of that range are usually well tolerated.
Many body lotions and serums marketed for stretch marks contain niacinamide alongside other active ingredients like collagen peptides, hyaluronic acid, or vitamin E. This combination approach makes sense given that no single ingredient has proven sufficient on its own. Hyaluronic acid adds deep hydration that plumps the skin’s surface, peptides signal collagen production, and niacinamide handles barrier repair and inflammation.
Safety During Pregnancy
Since pregnancy is one of the most common triggers for stretch marks, safety during pregnancy matters. Topical niacinamide is classified as acceptable for use during pregnancy by Australia’s drug regulatory authority, and the U.S. FDA has not flagged concerns. Niacinamide is a form of vitamin B3, an essential nutrient the body already uses for basic cellular functions. It does cross the placenta, with slightly higher concentrations found in the fetus than the mother, but deficiency during pregnancy is considered more of a concern than supplementation.
Realistic Expectations
Niacinamide is a solid supporting ingredient for stretch mark care, not a standalone solution. Its strength is in creating conditions where skin can repair itself more effectively: less inflammation, a stronger barrier, better hydration, and protection of existing collagen. If you’re using it on newer stretch marks alongside other active ingredients, you have a reasonable chance of seeing improvements in redness, texture, and overall skin quality in the area.
For older white stretch marks, niacinamide can improve the feel and hydration of the skin but is unlikely to make the marks disappear. Procedures like microneedling, laser therapy, or radiofrequency treatments have more evidence behind them for mature stretch marks, because they physically stimulate collagen remodeling deep in the dermis in a way that topical products cannot reach. Using niacinamide-containing products alongside these treatments could support recovery and overall skin health, but the heavy lifting for old marks comes from the procedure itself.