diff --git a/pkg/phlaredb/block_querier_test.go b/pkg/phlaredb/block_querier_test.go
index b0a09ca2e..d8939b47f 100644
--- a/pkg/phlaredb/block_querier_test.go
+++ b/pkg/phlaredb/block_querier_test.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/prometheus/client_golang/prometheus"
 	"github.com/samber/lo"
 	"github.com/stretchr/testify/require"
 
@@ -20,7 +21,7 @@ func TestInMemoryReader(t *testing.T) {
 		MaxBufferRowCount: defaultParquetConfig.MaxBufferRowCount / 1024,
 		MaxRowGroupBytes:  defaultParquetConfig.MaxRowGroupBytes / 1024,
 		MaxBlockBytes:     defaultParquetConfig.MaxBlockBytes,
-	}))
+	}, newHeadMetrics(prometheus.NewRegistry())))
 	rewrites := &rewriter{}
 	rgCount := 5
 	for i := 0; i < rgCount*st.cfg.MaxBufferRowCount; i++ {
diff --git a/pkg/phlaredb/deduplicating_slice.go b/pkg/phlaredb/deduplicating_slice.go
index 8dfe5d8a7..4be7431c1 100644
--- a/pkg/phlaredb/deduplicating_slice.go
+++ b/pkg/phlaredb/deduplicating_slice.go
@@ -37,9 +37,10 @@ type deduplicatingSlice[M Models, K comparable, H Helper[M, K], P schemav1.Persi
 	persister P
 	helper    H
 
-	file   *os.File
-	cfg    *ParquetConfig
-	writer *parquet.GenericWriter[P]
+	file    *os.File
+	cfg     *ParquetConfig
+	metrics *headMetrics
+	writer  *parquet.GenericWriter[P]
 
 	buffer      *parquet.Buffer
 	rowsFlushed int
@@ -57,8 +58,9 @@ func (s *deduplicatingSlice[M, K, H, P]) Size() uint64 {
 	return s.size.Load()
 }
 
-func (s *deduplicatingSlice[M, K, H, P]) Init(path string, cfg *ParquetConfig) error {
+func (s *deduplicatingSlice[M, K, H, P]) Init(path string, cfg *ParquetConfig, metrics *headMetrics) error {
 	s.cfg = cfg
+	s.metrics = metrics
 	file, err := os.OpenFile(filepath.Join(path, s.persister.Name()+block.ParquetSuffix), os.O_RDWR|os.O_CREATE|os.O_EXCL, 0o644)
 	if err != nil {
 		return err
@@ -214,7 +216,7 @@ func (s *deduplicatingSlice[M, K, H, P]) ingest(_ context.Context, elems []M, re
 			posSlice++
 
 			// increase size of stored data
-			s.size.Add(s.helper.size(elems[pos]))
+			s.metrics.sizeBytes.WithLabelValues(s.Name()).Set(float64(s.size.Add(s.helper.size(elems[pos]))))
 		}
 		s.lock.Unlock()
 	}
diff --git a/pkg/phlaredb/head.go b/pkg/phlaredb/head.go
index 5e4b2f586..75a532520 100644
--- a/pkg/phlaredb/head.go
+++ b/pkg/phlaredb/head.go
@@ -111,7 +111,7 @@ type Table interface {
 	Name() string
 	Size() uint64       // Size estimates the uncompressed byte size of the table in memory and on disk.
 	MemorySize() uint64 // MemorySize estimates the uncompressed byte size of the table in memory.
-	Init(path string, cfg *ParquetConfig) error
+	Init(path string, cfg *ParquetConfig, metrics *headMetrics) error
 	Flush(context.Context) (numRows uint64, numRowGroups uint64, err error)
 	Close() error
 }
@@ -173,7 +173,6 @@ func NewHead(phlarectx context.Context, cfg Config, limiter TenantLimiter) (*Hea
 	}
 	h.headPath = filepath.Join(cfg.DataPath, pathHead, h.meta.ULID.String())
 	h.localPath = filepath.Join(cfg.DataPath, pathLocal, h.meta.ULID.String())
-	h.metrics.setHead(h)
 
 	if cfg.Parquet != nil {
 		h.parquetConfig = cfg.Parquet
@@ -199,7 +198,7 @@ func NewHead(phlarectx context.Context, cfg Config, limiter TenantLimiter) (*Hea
 		h.profiles,
 	}
 	for _, t := range h.tables {
-		if err := t.Init(h.headPath, h.parquetConfig); err != nil {
+		if err := t.Init(h.headPath, h.parquetConfig, h.metrics); err != nil {
 			return nil, err
 		}
 	}
diff --git a/pkg/phlaredb/metrics.go b/pkg/phlaredb/metrics.go
index bcbc45463..c2471b5be 100644
--- a/pkg/phlaredb/metrics.go
+++ b/pkg/phlaredb/metrics.go
@@ -4,10 +4,10 @@ import (
 	"context"
 
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
 
 	phlarecontext "github.com/grafana/phlare/pkg/phlare/context"
 	"github.com/grafana/phlare/pkg/phlaredb/query"
+	"github.com/grafana/phlare/pkg/util"
 )
 
 type contextKey uint8
@@ -18,12 +18,10 @@ const (
 )
 
 type headMetrics struct {
-	head *Head
-
-	series        prometheus.GaugeFunc
+	series        prometheus.Gauge
 	seriesCreated *prometheus.CounterVec
 
-	profiles        prometheus.GaugeFunc
+	profiles        prometheus.Gauge
 	profilesCreated *prometheus.CounterVec
 
 	sizeBytes   *prometheus.GaugeVec
@@ -35,70 +33,66 @@ type headMetrics struct {
 
 func newHeadMetrics(reg prometheus.Registerer) *headMetrics {
 	m := &headMetrics{
-		seriesCreated: promauto.With(reg).NewCounterVec(prometheus.CounterOpts{
+		seriesCreated: prometheus.NewCounterVec(prometheus.CounterOpts{
 			Name: "phlare_tsdb_head_series_created_total",
 			Help: "Total number of series created in the head",
 		}, []string{"profile_name"}),
-		rowsWritten: promauto.With(reg).NewCounterVec(
+		rowsWritten: prometheus.NewCounterVec(
 			prometheus.CounterOpts{
 				Name: "phlare_rows_written",
 				Help: "Number of rows written to a parquet table.",
 			},
 			[]string{"type"}),
-		profilesCreated: promauto.With(reg).NewCounterVec(prometheus.CounterOpts{
+		profilesCreated: prometheus.NewCounterVec(prometheus.CounterOpts{
 			Name: "phlare_head_profiles_created_total",
 			Help: "Total number of profiles created in the head",
 		}, []string{"profile_name"}),
-		sampleValuesIngested: promauto.With(reg).NewCounterVec(
+		sampleValuesIngested: prometheus.NewCounterVec(
 			prometheus.CounterOpts{
 				Name: "phlare_head_ingested_sample_values_total",
 				Help: "Number of sample values ingested into the head per profile type.",
 			},
 			[]string{"profile_name"}),
-		sampleValuesReceived: promauto.With(reg).NewCounterVec(
+		sampleValuesReceived: prometheus.NewCounterVec(
 			prometheus.CounterOpts{
 				Name: "phlare_head_received_sample_values_total",
 				Help: "Number of sample values received into the head per profile type.",
 			},
 			[]string{"profile_name"}),
-
-		// this metric is not registered using promauto, as it has a callback into the header
 		sizeBytes: prometheus.NewGaugeVec(
 			prometheus.GaugeOpts{
 				Name: "phlare_head_size_bytes",
 				Help: "Size of a particular in memory store within the head phlaredb block.",
 			},
 			[]string{"type"}),
+		series: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "phlare_tsdb_head_series",
+			Help: "Total number of series in the head block.",
+		}),
+		profiles: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "phlare_head_profiles",
+			Help: "Total number of profiles in the head block.",
+		}),
 	}
 
-	// metrics that call into the head
-	m.series = promauto.With(reg).NewGaugeFunc(prometheus.GaugeOpts{
-		Name: "phlare_tsdb_head_series",
-		Help: "Total number of series in the head block.",
-	}, func() float64 {
-		if m.head == nil {
-			return 0.0
-		}
-		return float64(m.head.profiles.index.totalSeries.Load())
-	})
-	m.profiles = promauto.With(reg).NewGaugeFunc(prometheus.GaugeOpts{
-		Name: "phlare_head_profiles",
-		Help: "Total number of profiles in the head block.",
-	}, func() float64 {
-		if m.head == nil {
-			return 0.0
-		}
-		return float64(m.head.profiles.index.totalProfiles.Load())
-	})
-
-	if reg != nil {
-		reg.MustRegister(
-			m,
-		)
-	}
+	m.register(reg)
 	return m
 }
 
+func (m *headMetrics) register(reg prometheus.Registerer) {
+	if reg == nil {
+		return
+	}
+	m.series = util.RegisterOrGet(reg, m.series)
+	m.seriesCreated = util.RegisterOrGet(reg, m.seriesCreated)
+	m.profiles = util.RegisterOrGet(reg, m.profiles)
+	m.profilesCreated = util.RegisterOrGet(reg, m.profilesCreated)
+	m.sizeBytes = util.RegisterOrGet(reg, m.sizeBytes)
+	m.rowsWritten = util.RegisterOrGet(reg, m.rowsWritten)
+	m.sampleValuesIngested = util.RegisterOrGet(reg, m.sampleValuesIngested)
+	m.sampleValuesReceived = util.RegisterOrGet(reg, m.sampleValuesReceived)
+}
+
 func contextWithHeadMetrics(ctx context.Context, m *headMetrics) context.Context {
 	return context.WithValue(ctx, headMetricsContextKey, m)
 }
@@ -111,24 +105,6 @@ func contextHeadMetrics(ctx context.Context) *headMetrics {
 	return m
 }
 
-func (m *headMetrics) setHead(head *Head) *headMetrics {
-	m.head = head
-	return m
-}
-
-func (m *headMetrics) Describe(ch chan<- *prometheus.Desc) {
-	m.sizeBytes.Describe(ch)
-}
-
-func (m *headMetrics) Collect(ch chan<- prometheus.Metric) {
-	if m.head != nil {
-		for _, t := range m.head.tables {
-			m.sizeBytes.WithLabelValues(t.Name()).Set(float64(t.MemorySize()))
-		}
-	}
-	m.sizeBytes.Collect(ch)
-}
-
 type blocksMetrics struct {
 	query *query.Metrics
 
@@ -136,13 +112,15 @@ type blocksMetrics struct {
 }
 
 func newBlocksMetrics(reg prometheus.Registerer) *blocksMetrics {
-	return &blocksMetrics{
+	m := &blocksMetrics{
 		query: query.NewMetrics(reg),
-		blockOpeningLatency: promauto.With(reg).NewHistogram(prometheus.HistogramOpts{
+		blockOpeningLatency: prometheus.NewHistogram(prometheus.HistogramOpts{
 			Name: "phlaredb_block_opening_duration",
 			Help: "Latency of opening a block in seconds",
 		}),
 	}
+	m.blockOpeningLatency = util.RegisterOrGet(reg, m.blockOpeningLatency)
+	return m
 }
 
 func contextWithBlockMetrics(ctx context.Context, m *blocksMetrics) context.Context {
diff --git a/pkg/phlaredb/metrics_test.go b/pkg/phlaredb/metrics_test.go
new file mode 100644
index 000000000..45fb92159
--- /dev/null
+++ b/pkg/phlaredb/metrics_test.go
@@ -0,0 +1,26 @@
+package phlaredb
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/testutil"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMultipleRegistrationMetrics(t *testing.T) {
+	reg := prometheus.NewRegistry()
+	m1 := newHeadMetrics(reg)
+	m2 := newHeadMetrics(reg)
+
+	m1.profilesCreated.WithLabelValues("test").Inc()
+	m2.profilesCreated.WithLabelValues("test").Inc()
+
+	// collect metrics and compare them
+	require.NoError(t, testutil.GatherAndCompare(reg, strings.NewReader(`
+# HELP phlare_head_profiles_created_total Total number of profiles created in the head
+# TYPE phlare_head_profiles_created_total counter
+phlare_head_profiles_created_total{profile_name="test"} 2
+`), "phlare_head_profiles_created_total"))
+}
diff --git a/pkg/phlaredb/profile_store.go b/pkg/phlaredb/profile_store.go
index f9ee30a48..021679dfe 100644
--- a/pkg/phlaredb/profile_store.go
+++ b/pkg/phlaredb/profile_store.go
@@ -80,7 +80,7 @@ func (s *profileStore) MemorySize() uint64 {
 }
 
 // resets the store
-func (s *profileStore) Init(path string, cfg *ParquetConfig) (err error) {
+func (s *profileStore) Init(path string, cfg *ParquetConfig, metrics *headMetrics) (err error) {
 	// close previous iteration
 	if err := s.Close(); err != nil {
 		return err
@@ -97,6 +97,7 @@ func (s *profileStore) Init(path string, cfg *ParquetConfig) (err error) {
 
 	s.path = path
 	s.cfg = cfg
+	s.metrics = metrics
 
 	s.slice = s.slice[:0]
 
@@ -256,7 +257,7 @@ func (s *profileStore) cutRowGroup() (err error) {
 	// reset slice and metrics
 	s.slice = s.slice[:0]
 	s.size.Store(0)
-
+	s.metrics.sizeBytes.WithLabelValues(s.Name()).Set(0)
 	return nil
 }
 
@@ -312,7 +313,7 @@ func (s *profileStore) ingest(_ context.Context, profiles []*schemav1.Profile, l
 
 		// increase size of stored data
 		addedBytes := s.helper.size(profiles[pos])
-		s.size.Add(addedBytes)
+		s.metrics.sizeBytes.WithLabelValues(s.Name()).Set(float64(s.size.Add(addedBytes)))
 		s.totalSize.Add(addedBytes)
 
 		// add to slice
diff --git a/pkg/phlaredb/profile_store_test.go b/pkg/phlaredb/profile_store_test.go
index 05b1a53ab..46adf5db7 100644
--- a/pkg/phlaredb/profile_store_test.go
+++ b/pkg/phlaredb/profile_store_test.go
@@ -141,7 +141,7 @@ func TestProfileStore_RowGroupSplitting(t *testing.T) {
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			path := t.TempDir()
-			require.NoError(t, store.Init(path, tc.cfg))
+			require.NoError(t, store.Init(path, tc.cfg, newHeadMetrics(prometheus.NewRegistry())))
 
 			for i := 0; i < 100; i++ {
 				p := tc.values(i)
@@ -193,7 +193,7 @@ func TestProfileStore_Ingestion_SeriesIndexes(t *testing.T) {
 		store = newProfileStore(ctx)
 	)
 	path := t.TempDir()
-	require.NoError(t, store.Init(path, defaultParquetConfig))
+	require.NoError(t, store.Init(path, defaultParquetConfig, newHeadMetrics(prometheus.NewRegistry())))
 
 	for i := 0; i < 9; i++ {
 		p := threeProfileStreams(i)
diff --git a/pkg/phlaredb/profiles.go b/pkg/phlaredb/profiles.go
index c685079f6..91b77b885 100644
--- a/pkg/phlaredb/profiles.go
+++ b/pkg/phlaredb/profiles.go
@@ -178,7 +178,7 @@ func (pi *profilesIndex) Add(ps *schemav1.Profile, lbs phlaremodel.Labels, profi
 			profilesOnDisk: make([]*rowRange, pi.rowGroupsOnDisk),
 		}
 		pi.profilesPerFP[ps.SeriesFingerprint] = profiles
-		pi.totalSeries.Inc()
+		pi.metrics.series.Set(float64(pi.totalSeries.Inc()))
 		pi.metrics.seriesCreated.WithLabelValues(profileName).Inc()
 	}
 
@@ -190,7 +190,7 @@ func (pi *profilesIndex) Add(ps *schemav1.Profile, lbs phlaremodel.Labels, profi
 		profiles.maxTime = ps.TimeNanos
 	}
 
-	pi.totalProfiles.Inc()
+	pi.metrics.profiles.Set(float64(pi.totalProfiles.Inc()))
 	pi.metrics.profilesCreated.WithLabelValues(profileName).Inc()
 }
 
diff --git a/pkg/phlaredb/querier_test.go b/pkg/phlaredb/querier_test.go
index a90c418da..335964ffa 100644
--- a/pkg/phlaredb/querier_test.go
+++ b/pkg/phlaredb/querier_test.go
@@ -19,9 +19,7 @@ import (
 )
 
 func TestQueryIndex(t *testing.T) {
-	head := newTestHead(t)
-
-	a, err := newProfileIndex(32, newHeadMetrics(prometheus.NewRegistry()).setHead(head.Head))
+	a, err := newProfileIndex(32, newHeadMetrics(prometheus.NewRegistry()))
 	require.NoError(t, err)
 
 	for j := 0; j < 10; j++ {
diff --git a/pkg/phlaredb/query/metrics.go b/pkg/phlaredb/query/metrics.go
index f341f0794..af4fdb2f1 100644
--- a/pkg/phlaredb/query/metrics.go
+++ b/pkg/phlaredb/query/metrics.go
@@ -4,7 +4,8 @@ import (
 	"context"
 
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
+
+	"github.com/grafana/phlare/pkg/util"
 )
 
 type contextKey uint8
@@ -18,12 +19,14 @@ type Metrics struct {
 }
 
 func NewMetrics(reg prometheus.Registerer) *Metrics {
-	return &Metrics{
-		pageReadsTotal: promauto.With(reg).NewCounterVec(prometheus.CounterOpts{
+	m := &Metrics{
+		pageReadsTotal: prometheus.NewCounterVec(prometheus.CounterOpts{
 			Name: "phlaredb_page_reads_total",
 			Help: "Total number of pages read while querying",
 		}, []string{"table", "column"}),
 	}
+	m.pageReadsTotal = util.RegisterOrGet(reg, m.pageReadsTotal)
+	return m
 }
 
 func AddMetricsToContext(ctx context.Context, m *Metrics) context.Context {
diff --git a/pkg/util/prometheus.go b/pkg/util/prometheus.go
new file mode 100644
index 000000000..1143571db
--- /dev/null
+++ b/pkg/util/prometheus.go
@@ -0,0 +1,23 @@
+package util
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// RegisterOrGet registers the collector c with the provided registerer.
+// If the registerer is nil, the collector is returned without registration.
+// If the collector is already registered, the existing collector is returned.
+func RegisterOrGet[T prometheus.Collector](reg prometheus.Registerer, c T) T {
+	if reg == nil {
+		return c
+	}
+	err := reg.Register(c)
+	if err != nil {
+		already, ok := err.(prometheus.AlreadyRegisteredError)
+		if ok {
+			return already.ExistingCollector.(T)
+		}
+		panic(err)
+	}
+	return c
+}