Le minoxidil à 1 % fait-il repousser des cheveux, et fait-il aussi bien que les concentrations plus fortes ?
Le minoxidil à 1 % fait gagner plus de cheveux visibles (non duvet) que le placebo : +36,79 cheveux sur un cercle de 5,1 cm² à 26 semaines (Shupack 1987), et +180 contre +81 sous placebo dans un essai où le comptage inclut les cheveux intermédiaires (Olsen 1986). Il fait à peu près jeu égal avec le 2 % dans ces deux essais anciens (+36,79 contre +54,09 ; +180 contre +190 ; différences non significatives), mais moins bien que le 5 % dans un essai japonais plus récent : +21,2 contre +26,4 cheveux par cm² à 16 semaines (Tsuboi 2009).
Pourquoi ce niveau de preuve
Point de départ élevé : trois essais randomisés chez l'homme. Dégradé d'un niveau pour risque de biais : les deux essais des années 1980 sont à risque de biais élevé (comptage manuel, perdus de vue, financement partiel du fabricant) ; l'essai japonais, mieux conduit, compare le 1 % au 5 % et non au placebo. Les résultats vont dans le même sens : un effet réel, plus faible qu'au 5 %.
Niveau abaissé pour : risque de biais.
La conclusion est probablement juste, mais de nouveaux essais pourraient la nuancer.
À qui ça s’applique
Hommes de 18 à 49 ans, calvitie du vertex Hamilton III vertex ou IV, et hommes japonais adultes. Suivi de 16 à 26 semaines. Les gains comptés dans les essais des années 1980 ne se comparent pas aux chiffres au cm² des essais récents.
Les chiffres et leurs sources (8)
- Gain de cheveux non-duvet (cercle d'un pouce, 5,1 cm²)+81 cheveux sur 5,1 cm² Placebo face à Minoxidil topique 2 %
Voir la citation
Table III. Change from baseline target area hair Change from base- line target area hair Placebo 0.01% counts (N = 18) (N -- lS) Vellus (_SD) 9 (-+89) 37 (---59) Range - 154~. 195 -55, 164 Nonvellus (-+SD) 81 (---95) 48 (+57) Range -37,251 -52, 162 Total (__SD) 90 (___89) 84 (+-69) Range -40, 286 -21, 161 SD: Standard deviation.
Citation complémentaire (methode)
thus conservative. Univariate analyses were inspected for differences between dose levels with the use of Duncan's multiple range test at a significance level of 0.05. In addition, X2 tests were used to evaluate dif-
Citation complémentaire (significativite)
sis, the changes in (log) total and (log) nonvellus hair counts were significantly associated with treat- ment group (p = 0.04 and 0.02, respectively; Table III). The change from baseline vellus hair counts were not significantly associated with treat- ment group (p = 0.43). Duncan's multiple range test indicated that, for (log) total hair counts, the 2% minoxidil treatment group results were signif- icantly greater than the 0.01% and 0.1% topical minoxidil and placebo groups. The nonvellus (log) count was also significantly greater for the 2% topical minoxidil group than for the 0.01% topical minoxidil and placebo groups. There was no sta- tistically significant difference between the 2% and 1% topical minoxidil groups in terms of mean change in nonvellus or total hair counts from base- line to the end of this study.
Olsen EA, DeLong ER, Weiner MS. Dose-response study of topical minoxidil in male pattern baldness.. J Am Acad Dermatol 1986, DOI 10.1016/s0190-9622(86)70138-2. Citation reproduite au titre du droit de courte citation (article L122-5 du Code de la propriété intellectuelle).
- Gain de cheveux non-duvet (cercle d'un pouce, 5,1 cm²)+180 cheveux sur 5,1 cm² Minoxidil topique 1 % face à Placebo
Voir la citation
Table III. Change from baseline target area hair Change from base- line target area hair Placebo 0.01% counts (N = 18) (N -- lS) Vellus (_SD) 9 (-+89) 37 (---59) Range - 154~. 195 -55, 164 Nonvellus (-+SD) 81 (---95) 48 (+57) Range -37,251 -52, 162 Total (__SD) 90 (___89) 84 (+-69) Range -40, 286 -21, 161 SD: Standard deviation.
Citation complémentaire (valeur)
counts relative to treatment group Treatment group Topical minoxidil 2% 0.1% I 1% (N = 15) (N = 15) (N = 17) 11 (±87) -31 (+_92) -15 (+_ 121) - 184, 123 -245, 58 -342, 176 81 (_+68) 180 (_+ 126) 190 (___ 136) -32, 267 27, 395 38, 551 92 (-+79) 149 (+93) 175 (+99) -30, 209 15,362 38, 347
Olsen EA, DeLong ER, Weiner MS. Dose-response study of topical minoxidil in male pattern baldness.. J Am Acad Dermatol 1986, DOI 10.1016/s0190-9622(86)70138-2. Citation reproduite au titre du droit de courte citation (article L122-5 du Code de la propriété intellectuelle).
- Gain de cheveux non-duvet (cercle d'un pouce, 5,1 cm²)+190 cheveux sur 5,1 cm² Minoxidil topique 2 % face à Minoxidil topique 1 %
Voir la citation
Table III. Change from baseline target area hair Change from base- line target area hair Placebo 0.01% counts (N = 18) (N -- lS) Vellus (_SD) 9 (-+89) 37 (---59) Range - 154~. 195 -55, 164 Nonvellus (-+SD) 81 (---95) 48 (+57) Range -37,251 -52, 162 Total (__SD) 90 (___89) 84 (+-69) Range -40, 286 -21, 161 SD: Standard deviation.
Citation complémentaire (methode)
thus conservative. Univariate analyses were inspected for differences between dose levels with the use of Duncan's multiple range test at a significance level of 0.05. In addition, X2 tests were used to evaluate dif-
Citation complémentaire (significativite)
sis, the changes in (log) total and (log) nonvellus hair counts were significantly associated with treat- ment group (p = 0.04 and 0.02, respectively; Table III). The change from baseline vellus hair counts were not significantly associated with treat- ment group (p = 0.43). Duncan's multiple range test indicated that, for (log) total hair counts, the 2% minoxidil treatment group results were signif- icantly greater than the 0.01% and 0.1% topical minoxidil and placebo groups. The nonvellus (log) count was also significantly greater for the 2% topical minoxidil group than for the 0.01% topical minoxidil and placebo groups. There was no sta- tistically significant difference between the 2% and 1% topical minoxidil groups in terms of mean change in nonvellus or total hair counts from base- line to the end of this study.
Citation complémentaire (valeur)
counts relative to treatment group Treatment group Topical minoxidil 2% 0.1% I 1% (N = 15) (N = 15) (N = 17) 11 (±87) -31 (+_92) -15 (+_ 121) - 184, 123 -245, 58 -342, 176 81 (_+68) 180 (_+ 126) 190 (___ 136) -32, 267 27, 395 38, 551 92 (-+79) 149 (+93) 175 (+99) -30, 209 15,362 38, 347
Olsen EA, DeLong ER, Weiner MS. Dose-response study of topical minoxidil in male pattern baldness.. J Am Acad Dermatol 1986, DOI 10.1016/s0190-9622(86)70138-2. Citation reproduite au titre du droit de courte citation (article L122-5 du Code de la propriété intellectuelle).
- Gain de cheveux non-duvet (cercle d'un pouce, 5,1 cm²)+180 cheveux sur 5,1 cm² Minoxidil topique 1 % face à Minoxidil topique 2 %
Voir la citation
Table III. Change from baseline target area hair Change from base- line target area hair Placebo 0.01% counts (N = 18) (N -- lS) Vellus (_SD) 9 (-+89) 37 (---59) Range - 154~. 195 -55, 164 Nonvellus (-+SD) 81 (---95) 48 (+57) Range -37,251 -52, 162 Total (__SD) 90 (___89) 84 (+-69) Range -40, 286 -21, 161 SD: Standard deviation.
Citation complémentaire (methode)
thus conservative. Univariate analyses were inspected for differences between dose levels with the use of Duncan's multiple range test at a significance level of 0.05. In addition, X2 tests were used to evaluate dif-
Citation complémentaire (significativite)
sis, the changes in (log) total and (log) nonvellus hair counts were significantly associated with treat- ment group (p = 0.04 and 0.02, respectively; Table III). The change from baseline vellus hair counts were not significantly associated with treat- ment group (p = 0.43). Duncan's multiple range test indicated that, for (log) total hair counts, the 2% minoxidil treatment group results were signif- icantly greater than the 0.01% and 0.1% topical minoxidil and placebo groups. The nonvellus (log) count was also significantly greater for the 2% topical minoxidil group than for the 0.01% topical minoxidil and placebo groups. There was no sta- tistically significant difference between the 2% and 1% topical minoxidil groups in terms of mean change in nonvellus or total hair counts from base- line to the end of this study.
Citation complémentaire (valeur)
counts relative to treatment group Treatment group Topical minoxidil 2% 0.1% I 1% (N = 15) (N = 15) (N = 17) 11 (±87) -31 (+_92) -15 (+_ 121) - 184, 123 -245, 58 -342, 176 81 (_+68) 180 (_+ 126) 190 (___ 136) -32, 267 27, 395 38, 551 92 (-+79) 149 (+93) 175 (+99) -30, 209 15,362 38, 347
Olsen EA, DeLong ER, Weiner MS. Dose-response study of topical minoxidil in male pattern baldness.. J Am Acad Dermatol 1986, DOI 10.1016/s0190-9622(86)70138-2. Citation reproduite au titre du droit de courte citation (article L122-5 du Code de la propriété intellectuelle).
- Gain de cheveux non-duvet (cercle d'un pouce, 5,1 cm²)+36,79 cheveux sur 5,1 cm² Minoxidil topique 1 % face à Placebo
Voir la citation
Table Nonvellus hair counts before and after 6 months oftreatment Nonvellus bair counts After I Treatmentgroup N Before 6rno Placebo 11 1140 1305 Minoxidil 0.01% 12 1258 1273 Minoxidil 0.1%* 10 1591 1850 Minoxidil 1%* 14 1305 1820 Minoxidil 2%* 11 1020 1615 Mean increase Mean diameter Totalincrease inhaircounts ofbaldspot in baircounts (SD) (em) 165 15 (20.33) 7.6 15 1.25 (51.86) 7.4 259 25.9 (41.18) 6.2 515 36.79 (33.26) 7.1 595 54.09 (31.69) 6.2 *Statisticallysignificantdifferencefromplaceboand0.01%minoxidilgroups(0.01 > p <0.001).
Shupack JL, Kassimir JJ, Thirumoorthy T et al.. Dose-response study of topical minoxidil in male pattern alopecia.. J Am Acad Dermatol 1987, DOI 10.1016/s0190-9622(87)70086-3. Citation reproduite au titre du droit de courte citation (article L122-5 du Code de la propriété intellectuelle).
- Gain de cheveux non-duvet (cercle d'un pouce, 5,1 cm²)+54,09 cheveux sur 5,1 cm² Minoxidil topique 2 % face à Minoxidil topique 1 %
Voir la citation
Table Nonvellus hair counts before and after 6 months oftreatment Nonvellus bair counts After I Treatmentgroup N Before 6rno Placebo 11 1140 1305 Minoxidil 0.01% 12 1258 1273 Minoxidil 0.1%* 10 1591 1850 Minoxidil 1%* 14 1305 1820 Minoxidil 2%* 11 1020 1615 Mean increase Mean diameter Totalincrease inhaircounts ofbaldspot in baircounts (SD) (em) 165 15 (20.33) 7.6 15 1.25 (51.86) 7.4 259 25.9 (41.18) 6.2 515 36.79 (33.26) 7.1 595 54.09 (31.69) 6.2 *Statisticallysignificantdifferencefromplaceboand0.01%minoxidilgroups(0.01 > p <0.001).
Citation complémentaire (significativite)
groups. Atthesametimethere was nostatistically significantdifference (0.1 > P < 0.2) in thenon vellus hair increases between the 0.1%, 1%, and 2% minoxidil groups (Table II).
Shupack JL, Kassimir JJ, Thirumoorthy T et al.. Dose-response study of topical minoxidil in male pattern alopecia.. J Am Acad Dermatol 1987, DOI 10.1016/s0190-9622(87)70086-3. Citation reproduite au titre du droit de courte citation (article L122-5 du Code de la propriété intellectuelle).
- Gain de cheveux non-duvet depuis le départ+26,4 cheveux par cm² Minoxidil topique 5 % face à Minoxidil topique 1 %
Voir la citation
Table3. Meanchangefrombaselineinhaircountatweek16(fullanalysisset) One-samplet-test† Efficacyvariableinhaircount 5%(n=142) Non-vellushaircount 26.4±1.7(23.1–29.8) P<0.001 Vellushaircount )4.7±1.3()7.3to)2.1) P<0.001 Terminalhaircount 16.1±1.4(13.3–18.8) P<0.001 Non-terminalhaircount 4.9±1.7(1.6–8.2) P=0.004 Totalhaircount 22.3±1.4(19.5–25.1) P<0.001 1%(n=144) Two-samplet-test‡ 21.2±1.5(18.3–24.1) 5.2(0.8–9.6) P<0.001 P=0.020 )4.0±1.2()6.5to)1.6) )0.7()4.2to2.9) P=0.001 P=0.712 12.2±1.0(10.2–14.2) 3.9(0.5–7.3) P<0.001 P=0.026 3.0±1.3(0.4–5.7) 1.9()2.4to6.1) P=0.025 P=0.384 17.2±1.3(14.6–19.8) 5.1(1.3–8.8) P<0.001 P=0.009 †Mean±standarderror(one-side95%confidenceinterval).‡Differenceinchangebetweengroups(two-side95%confidenceinterval).
Tsuboi R, Arano O, Nishikawa T et al.. Randomized clinical trial comparing 5% and 1% topical minoxidil for the treatment of androgenetic alopecia in Japanese men.. J Dermatol 2009, DOI 10.1111/j.1346-8138.2009.00673.x. Citation reproduite au titre du droit de courte citation (article L122-5 du Code de la propriété intellectuelle).
- Gain de cheveux non-duvet depuis le départ+21,2 cheveux par cm² Minoxidil topique 1 % face à Minoxidil topique 5 %
Voir la citation
Table3. Meanchangefrombaselineinhaircountatweek16(fullanalysisset) One-samplet-test† Efficacyvariableinhaircount 5%(n=142) Non-vellushaircount 26.4±1.7(23.1–29.8) P<0.001 Vellushaircount )4.7±1.3()7.3to)2.1) P<0.001 Terminalhaircount 16.1±1.4(13.3–18.8) P<0.001 Non-terminalhaircount 4.9±1.7(1.6–8.2) P=0.004 Totalhaircount 22.3±1.4(19.5–25.1) P<0.001 1%(n=144) Two-samplet-test‡ 21.2±1.5(18.3–24.1) 5.2(0.8–9.6) P<0.001 P=0.020 )4.0±1.2()6.5to)1.6) )0.7()4.2to2.9) P=0.001 P=0.712 12.2±1.0(10.2–14.2) 3.9(0.5–7.3) P<0.001 P=0.026 3.0±1.3(0.4–5.7) 1.9()2.4to6.1) P=0.025 P=0.384 17.2±1.3(14.6–19.8) 5.1(1.3–8.8) P<0.001 P=0.009 †Mean±standarderror(one-side95%confidenceinterval).‡Differenceinchangebetweengroups(two-side95%confidenceinterval).
Tsuboi R, Arano O, Nishikawa T et al.. Randomized clinical trial comparing 5% and 1% topical minoxidil for the treatment of androgenetic alopecia in Japanese men.. J Dermatol 2009, DOI 10.1111/j.1346-8138.2009.00673.x. Citation reproduite au titre du droit de courte citation (article L122-5 du Code de la propriété intellectuelle).