{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Tetrahydrobiopterin+%28BH4%29",
    "query": {
      "intervention": "Tetrahydrobiopterin (BH4)"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 61,
    "total_pages": 7,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Tetrahydrobiopterin+%28BH4%29&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-10-03T23:31:41.079Z",
  "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": "NCT01135186",
      "title": "Impact of KUVAN® on Gastric Relaxation in Women With Diabetic Gastroparesis.",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Gastroparesis"
      ],
      "interventions": [
        {
          "name": "sapropterin dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Stanford University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "65 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 65 Years · Female only"
      },
      "enrollment_count": 9,
      "start_date": "2010-05",
      "completion_date": "2012-11",
      "has_results": true,
      "last_update_posted_date": "2019-09-10",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 1,
      "location_summary": "Stanford, California",
      "locations": [
        {
          "city": "Stanford",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01135186"
    },
    {
      "nct_id": "NCT00435331",
      "title": "6R-BH4 Pulmonary Arterial Hypertension Study",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Pulmonary Arterial Hypertension"
      ],
      "interventions": [
        {
          "name": "sapropterin dihydrochloride (6R-BH4)",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Vanderbilt University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 14,
      "start_date": "2008-03",
      "completion_date": "2008-10",
      "has_results": false,
      "last_update_posted_date": "2013-06-19",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00435331"
    },
    {
      "nct_id": "NCT01425528",
      "title": "Study of Kuvan Treatment in Adults With GTPCH Deficiency",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "GTP Cyclohydrolase Deficiency"
      ],
      "interventions": [
        {
          "name": "Sapropterin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Utah",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 12,
      "start_date": "2011-08",
      "completion_date": "2013-08",
      "has_results": true,
      "last_update_posted_date": "2025-04-01",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 1,
      "location_summary": "Salt Lake City, Utah",
      "locations": [
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01425528"
    },
    {
      "nct_id": "NCT01412437",
      "title": "Neuroimaging and Neurocognitive Assessment and Response to Sapropterin Dihydrochloride Treatment in Phenylketonuria",
      "overall_status": "WITHDRAWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "PKU"
      ],
      "interventions": [
        {
          "name": "diet",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "sapropterin dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "DRUG"
      ],
      "sponsor": "Children's National Research Institute",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "40 Years",
        "sex": "ALL",
        "summary": "18 Years to 40 Years"
      },
      "enrollment_count": 0,
      "start_date": "2011-04",
      "completion_date": "2012-12",
      "has_results": false,
      "last_update_posted_date": "2014-12-17",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 1,
      "location_summary": "Washington D.C., District of Columbia",
      "locations": [
        {
          "city": "Washington D.C.",
          "state": "District of Columbia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01412437"
    },
    {
      "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": "2026-10-03T23:31:41.079Z",
      "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": "NCT00104260",
      "title": "Study to Evaluate the Response to and Safety of an 8-Day Course of Phenoptin™ Treatment in Subjects With Phenylketonuria",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Phenylketonurias"
      ],
      "interventions": [
        {
          "name": "sapropterin dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "8 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "8 Years and older"
      },
      "enrollment_count": 700,
      "start_date": "2004-12",
      "completion_date": "2005-11",
      "has_results": false,
      "last_update_posted_date": "2007-04-09",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 13,
      "location_summary": "Los Angeles, California • Oakland, California • New Haven, Connecticut + 10 more",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Oakland",
          "state": "California"
        },
        {
          "city": "New Haven",
          "state": "Connecticut"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00104260"
    },
    {
      "nct_id": "NCT01439555",
      "title": "Endothelial Facilitation in Alzheimer's Disease",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Alzheimer's Disease"
      ],
      "interventions": [
        {
          "name": "Simvastatin",
          "type": "DRUG"
        },
        {
          "name": "L-Arginine",
          "type": "DRUG"
        },
        {
          "name": "Tetrahydrobiopterin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Massachusetts, Worcester",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "55 Years",
        "maximum_age": "85 Years",
        "sex": "ALL",
        "summary": "55 Years to 85 Years"
      },
      "enrollment_count": 11,
      "start_date": "2011-11",
      "completion_date": "2017-11",
      "has_results": true,
      "last_update_posted_date": "2019-07-30",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 1,
      "location_summary": "Worcester, Massachusetts",
      "locations": [
        {
          "city": "Worcester",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01439555"
    },
    {
      "nct_id": "NCT00728676",
      "title": "Study to Evaluate the Effects of Kuvan on Individuals With Phenylketonuria (PKU) With Maladaptive Behaviors",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Phenylketonuria"
      ],
      "interventions": [],
      "intervention_types": [],
      "sponsor": "Shoji Yano",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 10,
      "start_date": "2008-08",
      "completion_date": "2010-05",
      "has_results": false,
      "last_update_posted_date": "2013-01-18",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 1,
      "location_summary": "Los Angeles, California",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00728676"
    },
    {
      "nct_id": "NCT00104247",
      "title": "Study to Evaluate the Safety and Efficacy of Phenoptin™ in Subjects With Phenylketonuria Who Have Elevated Phenylalanine Levels",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Phenylketonurias"
      ],
      "interventions": [
        {
          "name": "sapropterin dihydrochloride, 6R-BH4, tetrahydrobiopterin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "8 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "8 Years and older"
      },
      "enrollment_count": 89,
      "start_date": "2005-03",
      "completion_date": "2006-02",
      "has_results": true,
      "last_update_posted_date": "2014-07-23",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 13,
      "location_summary": "Los Angeles, California • Oakland, California • New Haven, Connecticut + 10 more",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Oakland",
          "state": "California"
        },
        {
          "city": "New Haven",
          "state": "Connecticut"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00104247"
    },
    {
      "nct_id": "NCT01617070",
      "title": "Effects of Kuvan on Melatonin Secretion",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Phenylketonuria (PKU)"
      ],
      "interventions": [
        {
          "name": "Kuvan",
          "type": "DRUG"
        },
        {
          "name": "Large Neutral Amino Acid Therapy",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "University of Southern California",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 10,
      "start_date": "2012-05",
      "completion_date": "2014-12",
      "has_results": true,
      "last_update_posted_date": "2016-11-18",
      "last_synced_at": "2026-10-03T23:31:41.079Z",
      "location_count": 1,
      "location_summary": "Los Angeles, California",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01617070"
    }
  ]
}