Nobody has been measured, changed their use, and then been measured again. That one sentence explains why both halves of this question are open, and why the confident answers you have been given in either direction came from somewhere other than research.
The brain half. The study everyone links to found less grey matter in the right caudate in men who reported more hours of use. It is 64 healthy men, scanned once, with exposure measured by asking them. Its own authors wrote, in the paper, that the difference could be a precondition that makes pornography consumption more rewarding — something that was there first — rather than something use caused. It has never been replicated. The only other structural study in this area found its differences in a different region, least pronounced in the pornography group of the three clinical groups it compared, and those authors also asked for longitudinal work to tell a pre-existing trait from a developed one.
So "porn damaged your brain" is not a finding. Neither is its mirror image. No study has found permanent change, and no study has been designed that could — which is a real limit on the reassurance available here, and it is better stated than papered over.
The erections half. Whether pornography causes erectile difficulty is genuinely contested: supportive case reports and clinician reports on one side, frequency-based population studies that have not produced consistent associations on the other. Whether stopping reverses it has never been tested with a controlled design. The reversal evidence usually quoted is three clinical reports in a single 2016 paper. Of those three men, one could not stop and no outcome was recorded; one improved after cutting down while simultaneously giving up a device his own physician had identified as the likelier cause; one reported improvement while an inpatient being treated for a suicide attempt, alcohol use and depression. None was assessed with a validated erectile-function measure.
Against that sits the one study that followed men over a year with a validated instrument, which found no relationship between any pornography variable and the trajectory of their erectile function. It cuts both ways, and both halves belong in the same breath: it is evidence against "you have broken something", and equally evidence against "stopping will fix it".
The difficulty is real. What is unproven is the explanation. Erectile problems have plenty of established physical causes, and deciding yours is the porn without anyone checking is how people miss something treatable.
What has actually been shown to change
The part that brought you to this page. Meta-analytic evidence supports CBT and ACT for problematic pornography use, and for the depressive symptoms that travel with it. Those studies carry a high risk of bias and small samples throughout, which is why this is the best-supported route rather than a proven one — and it is still a great deal more than exists for anything else on offer.
And if what you are measuring is a quiet stretch of libido, arousal or mood during abstinence: that is consistently reported in abstinence journals and has never been formally studied, so there is no established shape it is supposed to take and no month at which something is due.
Where the permanence story comes from. "You have damaged your brain, here is the reboot" is a sales structure before it is a claim, and it works because fear converts well. This is a paid subscription product, and this market — apps, blockers, coaching, residential programmes, supplements — has a financial incentive favouring exactly that framing. Naming that is a disclosure about the app rather than a research finding, and it is the reason this page does not end on reassurance either.
The honest close is the sentence that is true in all three directions at once: the thing you are afraid of has never been found, the thing you are hoping for has never been demonstrated, and the thing that has been demonstrated is that the distress and the compulsion respond to treatment.
Where this comes from
Read the full lesson: The dopamine story, corrected →
Sources and how strong they are (6)
- Well establishedNo study has found that pornography use permanently changes the brain, and no study has been designed that could. The finding usually cited for permanent damage — less grey matter in the right caudate in men reporting more hours of use — is a single cross-sectional scan of 64 healthy men, whose own authors wrote that it "could be a precondition that makes pornography consumption more rewarding" rather than a consequence of it. It has never been replicated. Five further structural studies of compulsive sexual behaviour have each found their differences somewhere else - left frontal pole, left amygdala, superior temporal gyrus, right posterior cingulate, right cerebellum - two of them increases in grey matter rather than decreases, and none of them found a structural difference in the right caudate. The left frontal pole result is the weakest of those five for this population: it comes from a pooled comparison of compulsive sexual behaviour disorder, gambling disorder and alcohol use disorder against controls in which the compulsive sexual behaviour group showed the least pronounced difference, and that study's own disorder-specific finding is a severity correlation in the right anterior cingulate. Every one is cross-sectional, in 17 to 30 patients, and their authors ask for longitudinal work to separate a pre-existing trait from a developed one. Nobody has scanned the same person twice.
- Kühn S & Gallinat J 2014, JAMA Psychiatry 71(7):827-834, doi:10.1001/jamapsychiatry.2014.93, PMID 24871202
- Draps M, Sescousse G, Potenza MN, et al. 2020, J Sex Med 17(9):1761-1769, doi:10.1016/j.jsxm.2020.05.007, PMID 32690426
- Schmidt C, Morris LS, Kvamme TL, Hall P, Birchard T, Voon V 2017, Hum Brain Mapp 38(3):1182-1190, doi:10.1002/hbm.23447, PMID 27787929, PMC5324617
- Seok JW & Sohn JH 2018, Brain Res 1684:30-39, doi:10.1016/j.brainres.2018.01.035, PMID 29421186
- Görts P, Savard J, Görts-Öberg K, Dhejne C, Arver S, Jokinen J, Ingvar M, Abé C 2023, J Behav Addict 12(1):278-287, doi:10.1556/2006.2023.00008, PMID 36943775, PMC10260207
- Engel J, Gkavanozi A, Veit M, Kneer J, Kruger THC, Sinke C 2023 (Sex@Brain), J Behav Addict 12(4):1032-1045, doi:10.1556/2006.2023.00056, PMID 37874642, PMC10786231
- Ince C, Antons S, Brand M, Gola M, Potenza MN, Kraus SW, Stark R, Grubbs JB, Bőthe B, et al. 2026, J Behav Addict 15(1):32-98, doi:10.1556/2006.2025.00337, PMID 41879870, PMC13132360
- Not a source for this claim, and must not be cited as one — Stavro, Pelletier & Potvin 2013, Addict Biol 18(2):203-213, PMID 22264351 (recovery of cognitive function in abstinent alcohol users)
- Not a source for this claim, and must not be cited as one — Volkow et al. 2001, J Neurosci 21(23):9414-9418, PMID 11717374 (partial recovery of striatal dopamine transporters in five abstinent methamphetamine users)
- Contrary evidence considered — Kampa M, Krikova K, Stark R & Klucken T 2026, J Behav Addict 15(1):445-458, doi:10.1556/2006.2025.00452, PMID 41805604, PMC13132397
- AnecdotalWhether sexual difficulties get better after cutting down or stopping has never been tested with a controlled design. The reversal evidence everyone quotes is three clinical reports in a single 2016 paper: of those three men, one could not stop and no improvement was recorded, one improved after cutting down while simultaneously giving up a sex toy his doctor had named as a cause alongside the pornography, and one reported improvement while an inpatient being treated for a suicide attempt, alcohol use and depression. None was assessed with a validated erectile-function measure. Against that, the one longitudinal study that did use a validated measure followed men over a year and found no relationship between any pornography variable and the course of their erectile function.
- Park BY, Wilson G, Berger J, et al. 2016, Behav Sci (Basel) 6(3):17, doi:10.3390/bs6030017, PMID 27527226, PMC5039517 (2018 correction: Behav Sci 8(6):55, doi:10.3390/bs8060055, PMID 29857562)
- Grubbs JB & Gola M 2019, J Sex Med 16(1):111-125, doi:10.1016/j.jsxm.2018.11.004, PMID 30621919
- Fernandez DP, Kuss DJ & Griffiths MD 2021, Arch Sex Behav 50(2):711-728, doi:10.1007/s10508-020-01858-w, PMID 33403533
- Bronner G & Ben-Zion IZ 2014, J Sex Med 11(7):1798-1806, doi:10.1111/jsm.12501, PMID 24674621
- Dwulit AD & Rzymski P 2019, J Clin Med 8(7):914, doi:10.3390/jcm8070914, PMID 31247949
- Also considered — Sniewski L & Farvid P 2019, Sexual Addiction & Compulsivity 26(3-4):191-210, doi:10.1080/10720162.2019.1645058
- Fernandez DP, Kuss DJ, Justice LV, Fernandez EF & Griffiths MD 2023, Arch Sex Behav 52(4):1819-1840, doi:10.1007/s10508-022-02519-w, PMID 36652136
- Mixed evidencePorn-induced erectile dysfunction is a clinical hypothesis supported by case reports and clinician reports. Frequency-based population studies have not produced consistent associations, and the one longitudinal study to measure erectile function with a validated instrument over a year found that self-reported problematic use correlated with erectile difficulty at any single moment, that mere use did not, and that no pornography variable predicted the trajectory of erectile function. It remains contested.
- Park BY, Wilson G, Berger J, Christman M, Reina B, Bishop F, Klam WP, Doan AP 2016, Behav Sci 6(3):17, doi:10.3390/bs6030017, PMID 27527226, PMC5039517 — carries a 2018 correction, Behav Sci 8(6):55, doi:10.3390/bs8060055, PMID 29857562, disclosing that co-author Gary Wilson is the author of Your Brain on Porn and removing the academic editor's name; see C58
- Cuts toward an association — Jacobs T, Geysemans B, Van Hal G, Glazemakers I, Fog-Poulsen K, Vermandel A, De Wachter S, De Win G 2021, JMIR Public Health Surveill 7(10):e32542, doi:10.2196/32542, PMID 34534092, PMC8569536
- A practitioner magazine commentary, not a peer-reviewed study — Kirby M 2021, Trends in Urology & Men's Health 12(2):6-10, doi:10.1002/tre.791
- Grubbs JB & Gola M 2019, J Sex Med 16(1):111-125, doi:10.1016/j.jsxm.2018.11.004, PMID 30621919
- Dwulit & Rzymski 2019, J Clin Med 8(7):914, PMID 31247949
- Landripet & Štulhofer 2015, J Sex Med 12(5):1136-1139, PMID 25816904
- Prause & Pfaus 2015, Sex Med 3(2):90-98, PMID 26185674
- Not a retraction — a published Comment on Prause & Pfaus 2015: Isenberg RA 2015, Sex Med 3(3):219-221, doi:10.1002/sm2.71
- Mixed evidenceMeta-analytic evidence supports CBT and ACT for problematic pornography use and related depressive symptoms, but the studies carry a high risk of bias and small samples.
- López-Pinar C, Esparza-Reig J & Bőthe B 2025, J Behav Addict 14(2):630-643, doi:10.1556/2006.2025.00018, PMID 40126561
- AnecdotalThe "flatline" — a period of dropped libido, mood or arousal during abstinence — is consistently reported in abstinence journals and is named in the review literature, but it has never been measured prospectively or in a general population.
- Fernandez DP, Kuss DJ & Griffiths MD 2021, Arch Sex Behav 50(2):711-728, doi:10.1007/s10508-020-01858-w, PMID 33403533, PMC7889567
- Mead D & Sharpe M 2020, Int J Environ Res Public Health 17(10):3462, doi:10.3390/ijerph17103462
- Ince C, Antons S, Ashton S, Borgogna NC, Brand M, Briken P, Castro-Calvo J, Chen L, Coleman E, Efrati Y, Fernández DP, Fuss J et al. 2026, J Behav Addict 15(1):32-98, doi:10.1556/2006.2025.00337, PMID 41879870, PMC13132360
- Well establishedNightshore is a paid subscription product, and companies in this market - apps, blockers, coaching, residential programmes, supplements - have a financial incentive favouring the addiction framing. This is a disclosure about the app and the market it sits in, not an empirical finding. This applies with extra force to AI sexual products, whose commercial model is open-ended generation: a generator has no last video the way a tube site has a last page, and the same incentive that favours the addiction framing here favours unlimited engagement there. Both statements are observations about who profits from what, not measured findings.
- docs/premium.md — this app's own commercial position, which the first half of the entry is a fact about
- Lapointe et al. 2025, doi:10.1007/s10508-025-03099-1
- Not cited as evidence of an effect, and not peer reviewed — Knox et al. 2025, arXiv:2511.14972
- Not cited as evidence of an effect, and not peer reviewed — Chen & Hiniker 2026, arXiv:2609.14696
More evidence in the app.
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