Alternativen zu Cysteamine (topical)

Daily broad-spectrum sunscreen — the single most evidence-based anti-aging skincare step there is, and the one most 'anti-aging' actives are really just trying to compensate for. The honest framing: this is the only topical on this list backed by a proper randomized controlled trial for skin aging itself. In the landmark Hughes 2013 trial (n=903), people randomized to daily sunscreen showed 24% less photoaging over 4.5 years — and no detectable increase in skin aging at all — while the mechanism (UV → matrix-metalloproteinase activation → collagen breakdown) is textbook. The same trial cohort also had less skin cancer. The honest caveats: the benefit is overwhelmingly prevention, not reversal of existing damage; real-world results depend entirely on applying enough and reapplying; and chemical (organic) UV filters are systemically absorbed above an FDA testing threshold (clinical significance unknown — mineral zinc-oxide/titanium-dioxide filters sidestep this). If you do one thing for your skin, it's this.

A topical skincare acid applied to the skin for rosacea, acne, and uneven tone — unusual among 'cosmetic' actives because it has genuine drug-grade evidence. Azelaic acid is a naturally occurring dicarboxylic acid that is anti-inflammatory, antimicrobial, and a tyrosinase inhibitor. It is sold both as an over-the-counter cosmetic (around 10%) AND as a 15-20% prescription medication. The honest framing: the strongest, best-replicated evidence — including double-blind phase III trials and a Cochrane review that rated it high-quality for papulopustular rosacea — used the PRESCRIPTION strengths (15-20%), not the ~10% OTC cosmetic form. It also has solid evidence for acne and melasma. Head-to-head it is beaten for acne (by benzoyl peroxide + clindamycin) and tends to cause more local irritation (burning, stinging) than several comparators. For rosacea or persistent acne, the prescription form under a clinician is the evidence-based route.

The long-standing gold-standard topical skin-lightening agent for melasma and hyperpigmentation — and now a regulated drug, not a cosmetic. Hydroquinone (HQ) competitively inhibits tyrosinase and is toxic to overactive pigment cells. The honest framing: it is the most rigorously studied and most effective topical depigmenter — a large pivotal RCT, a Cochrane review, and recent meta-analyses all use HQ 4% (and the 'Kligman' triple-combination with a retinoid + steroid) as the benchmark that newer agents are measured against and rarely beat. But it carries real liabilities: irritation, rebound pigmentation, and — with prolonged or high-strength use — a disfiguring complication called exogenous ochronosis. For these reasons it was pulled from US over-the-counter sale in 2020 (now prescription-only) and is restricted in the EU and elsewhere. Effective, but for monitored, time-limited medical use.

A topical alpha-hydroxy acid (AHA) applied to the skin for texture, tone, and mild photoaging — a cosmetic exfoliant, not ingested. Glycolic acid is the smallest AHA; it loosens the 'glue' between dead surface cells (a targeted breakdown of corneocyte desmosomes), driving exfoliation and, at higher strengths, dermal changes. The honest framing: at leave-on cosmetic strengths (5-15% daily cream) the benefit is real but modest — significant for skin texture and discoloration, but not for wrinkles, and weaker than a retinoid. The stronger, clearer evidence is for in-office peels (20-70%), which are a different, more irritating intervention. It is acidic and can sting, and AHAs increase sun sensitivity. These are cosmetic appearance outcomes, not health outcomes.

A topical skin-brightening active applied to the skin for hyperpigmentation and melasma — a cosmetic, not ingested. Kojic acid is a fungal-derived tyrosinase inhibitor (it chelates the copper at the enzyme's active site, slowing melanin production). It has genuine human RCT support for melasma and appears in a large 2023 meta-analysis with a statistically significant effect. The honest framing: the effect size is modest — the weakest of the major depigmenting agents in that meta-analysis — and most of the strong evidence is for kojic acid ADDED to hydroquinone/glycolic-acid bases rather than used alone. Contact sensitisation (allergy) is a well-documented downside of long-term use. These are cosmetic appearance outcomes, not health outcomes.

A topical cosmetic form of vitamin B3 — a leave-on skincare active applied to the skin, NOT (in this context) an ingested supplement. Niacinamide (nicotinamide) is one of the better-evidenced cosmetic actives: short, double-blind, split-face trials — many run or funded by Procter & Gamble — show real but modest improvements in hyperpigmentation, fine lines, sallowness, sebum, and the skin barrier at roughly 2-5%. It is mechanistically plausible (it boosts ceramide/barrier-lipid synthesis and reduces transfer of pigment to skin cells) and consistently well tolerated. The honest framing: it is generally an ADJUVANT rather than a first-line active — in head-to-head pigmentation trials hydroquinone still edges it out — and most trials are small and industry-linked. These are cosmetic appearance outcomes, not health outcomes. (Separately, ORAL nicotinamide has its own, unrelated evidence for reducing non-melanoma skin cancers — that is a different, ingested use and not what this topical entry covers.)

A topical brightening active applied to the skin for melasma and stubborn pigmentation — a cosmetic/derm active, not (in this context) ingested. Tranexamic acid (a drug best known as an antifibrinolytic) interrupts the plasmin signalling that activates melanocytes, reducing pigment. The honest framing: topical TXA performs comparably to hydroquinone in small split-face trials and is very well tolerated, but the strongest melasma evidence — a placebo-controlled RCT and favorable meta-analysis rankings — is for ORAL tranexamic acid, not topical, and topical efficacy is limited by skin penetration. A network meta-analysis ranks topical TXA below oral TXA, lasers, and triple-combination cream. These are cosmetic appearance outcomes, not health outcomes.

Topical vitamin C — a leave-on antioxidant skincare active applied to the skin, NOT (in this context) an oral vitamin C supplement. As L-ascorbic acid or a stabilized derivative, it has a strong rationale: vitamin C is an essential cofactor for collagen synthesis and a free-radical scavenger that supports photoprotection. Small, vehicle-controlled split-face trials show genuine but modest improvements in wrinkles, skin texture, and pigmentation, and it has a consistent brightening/depigmenting signal. The honest framing: the whole topical-vitamin-C trial base is tiny (a systematic review pooled ~7 studies and ~139 people), formulations are notoriously unstable (they oxidise and lose potency), and most positive trials combine vitamin C with vitamin E, ferulic acid, or other actives — so vitamin-C-alone efficacy is hard to isolate. These are cosmetic appearance outcomes, not health outcomes, and it is not a sunscreen substitute.