{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Placebo+for+BH4",
    "query": {
      "intervention": "Placebo for BH4"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 13,
    "total_pages": 2,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Placebo+for+BH4&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-12T11:52:54.209Z",
  "attribution": "Data derived from public ClinicalTrials.gov records. The official record at https://clinicaltrials.gov/ remains the source of truth for current availability, contacts, and full study details.",
  "notes": [
    "This endpoint exposes only public summary fields — no participant contact emails, phone numbers, or scraped investigator contact details.",
    "For contact information and full protocol detail, follow each trial's `official_url` to the ClinicalTrials.gov record.",
    "This API is a navigational aid. It does not provide medical advice, eligibility determinations, or compensation guarantees."
  ],
  "trials": [
    {
      "nct_id": "NCT00802893",
      "title": "Oral 6R-BH4 for the Treatment of Isolated Systolic Hypertension and Endothelial Dysfunction",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Isolated Systolic Hypertension",
        "Endothelial Dysfunction"
      ],
      "interventions": [
        {
          "name": "6R-BH4",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER"
      ],
      "sponsor": "Johns Hopkins University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "40 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "40 Years and older"
      },
      "enrollment_count": 3,
      "start_date": "2008-12",
      "completion_date": "2009-05",
      "has_results": true,
      "last_update_posted_date": "2017-08-21",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 1,
      "location_summary": "Baltimore, Maryland",
      "locations": [
        {
          "city": "Baltimore",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00802893"
    },
    {
      "nct_id": "NCT01356966",
      "title": "Exercise Intolerance in Renal Failure",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Kidney Failure, Chronic"
      ],
      "interventions": [
        {
          "name": "Tetrahydrobiopterin",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        },
        {
          "name": "Folate",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Emory University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "75 Years",
        "sex": "ALL",
        "summary": "18 Years to 75 Years"
      },
      "enrollment_count": 74,
      "start_date": "2011-05",
      "completion_date": "2014-05",
      "has_results": true,
      "last_update_posted_date": "2015-06-01",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 2,
      "location_summary": "Atlanta, Georgia • Decatur, Georgia",
      "locations": [
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "Decatur",
          "state": "Georgia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01356966"
    },
    {
      "nct_id": "NCT03136029",
      "title": "Exercise and NO in HFrEF",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "EARLY_PHASE1"
      ],
      "conditions": [
        "Heart Failure With Reduced Ejection Fraction"
      ],
      "interventions": [
        {
          "name": "Antioxidant",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Tetrahydrobiopterin (BH4)",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Exercise training",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "OTHER"
      ],
      "sponsor": "VA Office of Research and Development",
      "sponsor_class": "FED",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 68,
      "start_date": "2018-06-01",
      "completion_date": "2025-07-31",
      "has_results": false,
      "last_update_posted_date": "2025-08-06",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 1,
      "location_summary": "Salt Lake City, Utah",
      "locations": [
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03136029"
    },
    {
      "nct_id": "NCT00403494",
      "title": "A Phase 2 Study of the Effects of Sapropterin Dihydrochloride on Symptomatic Peripheral Arterial Disease",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Intermittent Claudication"
      ],
      "interventions": [
        {
          "name": "Placebo",
          "type": "OTHER"
        },
        {
          "name": "Sapropterin Dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "OTHER",
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "40 Years",
        "maximum_age": "80 Years",
        "sex": "ALL",
        "summary": "40 Years to 80 Years"
      },
      "enrollment_count": 190,
      "start_date": "2006-12",
      "completion_date": "2009-01",
      "has_results": true,
      "last_update_posted_date": "2021-01-07",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 17,
      "location_summary": "Scottsdale, Arizona • Sacramento, California • San Diego, California + 14 more",
      "locations": [
        {
          "city": "Scottsdale",
          "state": "Arizona"
        },
        {
          "city": "Sacramento",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Santa Ana",
          "state": "California"
        },
        {
          "city": "Santa Rosa",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00403494"
    },
    {
      "nct_id": "NCT00850070",
      "title": "Sapropterin as a Treatment for Autistic Disorder",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Autistic Disorder"
      ],
      "interventions": [
        {
          "name": "sapropterin",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "The Children's Health Council",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "3 Years",
        "maximum_age": "6 Years",
        "sex": "ALL",
        "summary": "3 Years to 6 Years"
      },
      "enrollment_count": 46,
      "start_date": "2009-03",
      "completion_date": "2011-10",
      "has_results": true,
      "last_update_posted_date": "2018-05-01",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 1,
      "location_summary": "Palo Alto, California",
      "locations": [
        {
          "city": "Palo Alto",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00850070"
    },
    {
      "nct_id": "NCT00789568",
      "title": "A Phase 1 Study to Evaluate Effects of Sapropterin Dihydrochloride on QTc Intervals in Healthy Adult Subjects",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Phenylketonuria"
      ],
      "interventions": [
        {
          "name": "sapropterin dihydrochloride",
          "type": "DRUG"
        },
        {
          "name": "Moxifloxacin",
          "type": "DRUG"
        },
        {
          "name": "Moxifloxacin placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 56,
      "start_date": "2008-10",
      "completion_date": "2009-10",
      "has_results": false,
      "last_update_posted_date": "2021-07-23",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 1,
      "location_summary": "Fargo, North Dakota",
      "locations": [
        {
          "city": "Fargo",
          "state": "North Dakota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00789568"
    },
    {
      "nct_id": "NCT06312748",
      "title": "Novel Approaches for Improving Vascular Function in Veterans With HFpEF",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Heart Failure With Preserved Ejection Fraction",
        "Inflammation"
      ],
      "interventions": [
        {
          "name": "L-Citrulline",
          "type": "DRUG"
        },
        {
          "name": "Placebo for L-Citrulline",
          "type": "DRUG"
        },
        {
          "name": "BH4",
          "type": "DRUG"
        },
        {
          "name": "Placebo for BH4",
          "type": "DRUG"
        },
        {
          "name": "Atorvastatin",
          "type": "DRUG"
        },
        {
          "name": "Placebo for Atorvastatin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "VA Office of Research and Development",
      "sponsor_class": "FED",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 90,
      "start_date": "2021-05-19",
      "completion_date": "2030-09-30",
      "has_results": false,
      "last_update_posted_date": "2026-04-23",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 1,
      "location_summary": "Salt Lake City, Utah",
      "locations": [
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06312748"
    },
    {
      "nct_id": "NCT02530996",
      "title": "Systemic Sclerosis (SSc) Vasculopathy: Improved Clinical Monitoring and Treatment",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Rheumatologic Disease"
      ],
      "interventions": [
        {
          "name": "BH4",
          "type": "DRUG"
        },
        {
          "name": "Vasculopathy assessment",
          "type": "DIAGNOSTIC_TEST"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIAGNOSTIC_TEST"
      ],
      "sponsor": "VA Office of Research and Development",
      "sponsor_class": "FED",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "95 Years",
        "sex": "ALL",
        "summary": "18 Years to 95 Years"
      },
      "enrollment_count": 12,
      "start_date": "2016-01-01",
      "completion_date": "2019-12-31",
      "has_results": true,
      "last_update_posted_date": "2021-04-05",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 1,
      "location_summary": "Salt Lake City, Utah",
      "locations": [
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02530996"
    },
    {
      "nct_id": "NCT00272792",
      "title": "Study of Phenoptin to Increase Phenylalanine Tolerance in Phenylketonuric Children on a Phenylalanine-restricted Diet",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Phenylketonurias"
      ],
      "interventions": [
        {
          "name": "Sapropterin Dihydrochloride",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "4 Years",
        "maximum_age": "12 Years",
        "sex": "ALL",
        "summary": "4 Years to 12 Years"
      },
      "enrollment_count": 45,
      "start_date": "2006-02",
      "completion_date": "2006-11",
      "has_results": true,
      "last_update_posted_date": "2015-08-13",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 9,
      "location_summary": "Los Angeles, California • Oakland, California • Sacramento, California + 6 more",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Oakland",
          "state": "California"
        },
        {
          "city": "Sacramento",
          "state": "California"
        },
        {
          "city": "San Jose",
          "state": "California"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00272792"
    },
    {
      "nct_id": "NCT02947750",
      "title": "Neurovascular Transduction During Exercise in Chronic Kidney Disease",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Renal Insufficiency, Chronic"
      ],
      "interventions": [
        {
          "name": "6R-BH4",
          "type": "DRUG"
        },
        {
          "name": "6R-BH4 placebo",
          "type": "OTHER"
        },
        {
          "name": "Folic acid",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Exercise training",
          "type": "OTHER"
        },
        {
          "name": "Stretching",
          "type": "OTHER"
        },
        {
          "name": "Histidine and beta-alanine supplementation",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Histidine and beta-alanine placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Emory University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "75 Years",
        "sex": "ALL",
        "summary": "18 Years to 75 Years"
      },
      "enrollment_count": 150,
      "start_date": "2016-10",
      "completion_date": "2027-04-30",
      "has_results": false,
      "last_update_posted_date": "2026-05-18",
      "last_synced_at": "2026-09-12T11:52:54.209Z",
      "location_count": 3,
      "location_summary": "Atlanta, Georgia • Decatur, Georgia",
      "locations": [
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "Decatur",
          "state": "Georgia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02947750"
    }
  ]
}