Inclusion Criteria:
Subjects must meet all of the following inclusion criteria to participate in this study.
1. The age at entry for trails involving adult subjects is 18-65 years (including both ends)；
2. According to ICHD-3(Headache Classification Committee of the International Headache Society,2018), individuals should be diagnosed with migraine without aura and/or migraine with aura, and should have a history of at least 1 year;
3. The age at first migraine onset should be \<50 years;
4. Migraine attacks ≥ 4 days/month and \< 15 days/month within 3 months prior to screening period (Refer to the definition of migraine days);
5. Within 3 months before entering the screening period, the number of headache (including migraine and other types of headache) attack days per month is less than 15 days/month (Refer to the definition of headache days);
6. Be willing to take effective contraceptive measures during the period of participating in this experiment and within 28 days after the last time taking investigational product;
7. Understand and abide by the research procedures and methods, voluntarily participate in this experiment, and sign the informed consent in writing, agreeing to enter the baseline period.
The following criteria must be met during the baseline period to be eligible for entering the randomized, double-blind, placebo-controlled trial of the drug:
8. Migraine days ≥4 and \<14 days within 4 weeks of baseline period(Evaluation based on the Annex 14.-Electronic Headache Diary);
9. Headache days \< 14 days within 4 weeks of baseline period;
10. Completion of at least 80% of the electronic diary within 4 weeks of the baseline period(Within 28 days of the baseline period, the electronic diary has been completed for at least 23 days), and the investigator believes that the subject is able to read, understand, and complete the study questionnaire and headache diary;
11. Understand and abide by the research procedures and methods, voluntarily participate in this experiment, and sign the informed consent in writing, agreeing to enter the randomized, double-blind, placebo-controlled trials of the drug.
Exclusion Criteria:
Subjects with any of the following cannot participate in this study:
1. Subject diagnosed with possible migraine according to ICHD-3(2018);
2. Current and previous diagnosis of primary headache, secondary headache, or painful cranial neuropathy other than migraine(diagnostic criteria are defined according to ICHD-3,2018);
3. Previous use of more than two of the following 7 drugs is ineffective after adequate use, the types of these drugs are as follows:
* Type 1: Divalproex, Sodium Valproate
* Type 2: Topiramate
* Type 3: Beta blockers(such as: Atenolol, Bisoprolol, Metoprolol, Nadolol, Nebivolol, Pindolol, Propranolol, Timolol)
* Type 4: Tricyclic antidepressants(TCA) (such as: Amitriptyline, Nortriptyline, Protriptyline)
* Type 5: Serotonin-norepinephrine reuptake inhibitors (SNRIs) (such as: Venlafaxine, Desvenlafaxine, Duloxetine, Milnacipran)
* Type 6: Flunarizine, Verapamil
* Type 7: lisinopril, Candesartan
* Type 8: Drugs acting on the CGRP pathway（Monoclonal antibodies and Gepants）
Definition of treatment failure: No reduction in headache frequency, duration, or severity after 6 weeks of administration of the above drugs.
The following conditions are not defined as treatment failure:
* Lack of sustained response to medication;
* Can not be tolerated dose of drug
4. Use of prohibited drugs, Chinese patent drug, Chinese herbal medicines, instruments or therapies, etc. 2 months before the baseline period or during the baseline period (more details are in Prohibited Drugs/Treatments);
5. Subjects who intend to undergo head, face or neck injections of therapeutic or cosmetic Botulinum Toxin(such as Dysport, Botox, Xeomin, Myobloc and JeuvwauTM) during the study period or within 4 months before screening;
6. Simultaneous use of two or more drugs that may have migraine preventive effects within 2 months before the start of the baseline period or during the baseline period (more details are in Annex- The List of Migraine Preventive Medications ) (If only one prophylactic drug is used, the dose must be stable for the two months prior to the baseline period and throughout the study);
7. The following occurred within two months prior to the start of the baseline period:
* Taking Ergotamines or Triptans for ≥10 days per month, or
* Taking NSAIDs alone for ≥15 days compound or preparation of NSAIDs≥10 days, or
* Taking Opioid or Barbiturate analgesics for ≥4 days per month
8. Fluvoxamine, ciprofloxacin (cytochrome oxidase P450IA2 inhibitor), fluoroquinolones, zileuton, antiarrhythmics (amiodarone, mexiletine, propafenone, and verapamil) , cimetidine, famotidine, acyclovir, ticlopidine, metoprolol, propranolol and other beta-blockers, clonidine and other alpha2-adrenergic agonists , Chinese patent medicine, Chinese herbal medicine, instrument or program (see 5.7.2 Prohibited Drugs/Treatment for details)
9. Subject has active chronic pain syndrome (eg, fibromyalgia, chronic pelvic pain, facial pain, etc.);
10. Subject has a history of mental illness (eg, schizophrenia or bipolar disorder) or PHQ-9 score≥15；Subjects PHQ-9 score\<15 are allowed to enter the double-blind treatment period if they had a history of anxiety or depression and were taking no more than one psychotropic drug (excluding contraindicated drugs) (Subjects must have taken a stable therapeutic dose within 3 months prior to the baseline period);
11. Have a serious neurological disorder other than migraines (Note: Do not rule out single children febrile convulsion);
12. Patients with a history of malignant tumour within five years prior to the screening period, excluding non-melanoma skin cancer, cervical or breast ductal carcinoma in situ;
13. The screening period meets any of the following laboratory values:
* Alanine transaminase (ALT) or aspartate aminotransferase (AST) \>1.5×（upper limit of normal, ULN）, or
* Total bilirubin(TBIL) \>1.5×ULN （Subjects with diagnosed Gilbert syndrome excluded）,or
* The creatinine clearance rate is less than 25 mg/min, and the creatinine clearance rate decreases by 50%;
14. Previous heart disease, heart failure, bradycardia, orthostatic hypotension and other types of hypotension, stroke, transient ischemic attack (TIA);
15. The subject has factors that the investigator believes may put the subject at significant risk or may confound the results of the study; The subject has any medical or other reasons for being unfit to participate in the study;
16. According to clinical interviews or C-SSRS questionnaires, the researcher believes that the subject is at risk of self-harm or harm to others;
17. Within 12 months before the screening period, according to the subject's medical records or the subject's self-reported history of drug or alcohol abuse;
18. Subjects expected to be pregnant or breastfeeding during the study period, or had a positive urine pregnancy test result at screening;
19. During the study period, female subjects of childbearing potential were reluctant to use an acceptable method of effective contraception; Infertile women are defined as follows:
* Have a history of menopause, defined as: Age: ≥55 years old, Menopause ≥12 months, or Age:\<55 years old, no spontaneous menstruation for at least 2 years，or Age:\<55 years old, have spontaneous menstruation in the past 1 year, but current is amenorrhea (spontaneous or secondary to hysterectomy), and abnormal postmenopausal Gonadotropin levels: luteinizing hormone(LH), follicle-stimulating hormone(FSH)\>40IU/L or postmenopausal estradiol level \<5ng/dL, or
* Have a history of bilateral oophorectomy, or
* Have a history of hysterectomy, or
* Have a history of bilateral salpingectomy
20. Subjects who participated in other clinical trials within 3 months before the screening period;
21. .Subjects who are allergic to tizanidine hydrochloride or tizanidine hydrochloride excipients;
22. Subjects who cannot maintain their original diet and living habits during the trial;
23. Subjects who intend to take estrogen and/or progesterone drugs during the screening period or after enrollment;
24. Subject is a researcher involved in the study or an immediate family member (parent, spouse, sibling or child).
